npm-check vulnerabilities

• Vulnerable module: merge-options
• Introduced through: merge-options@0.0.64

Detailed paths

• Introduced through: npm-check@5.7.0 > merge-options@0.0.64

Overview

Affected versions of merge-options are vulnerable to Prototype Pollution. Utilities function in all the listed modules can be tricked into modifying the prototype of "Object" when the attacker control part of the structure passed to these function. This can let an attacker add or modify existing property that will exist on all object.

PoC by HoLyVieR

var merge = require('merge-options');
var malicious_payload = '{"__proto__":{"oops":"It works !"}}';

var a = {};
console.log("Before : " + a.oops);
merge({}, JSON.parse(malicious_payload));
console.log("After : " + a.oops);

Remediation

Upgrade merge-options to version 1.0.1 or higher.

References

• HackerOne Report
• GitHub Commit

• Vulnerable module: lodash
• Introduced through: lodash@3.10.1 and inquirer@0.11.4

Detailed paths

• Introduced through: npm-check@4.1.4 > lodash@3.10.1
• Introduced through: npm-check@4.1.4 > inquirer@0.11.4 > lodash@3.10.1

Overview

lodash is a javaScript utility library delivering modularity, performance & extras.

Affected versions of this package are vulnerable to Prototype Pollution. The utilities function allow modification of the Object prototype. If an attacker can control part of the structure passed to this function, they could add or modify an existing property.

PoC by Olivier Arteau (HoLyVieR)

var _= require('lodash');
var malicious_payload = '{"__proto__":{"oops":"It works !"}}';

var a = {};
console.log("Before : " + a.oops);
_.merge({}, JSON.parse(malicious_payload));
console.log("After : " + a.oops);

Remediation

Upgrade lodash to version 4.17.5 or higher.

References

• HackerOne Report

• Vulnerable module: debug
• Introduced through: mquery@1.4.0 and mocha@2.5.3

Detailed paths

• Introduced through: mongoose@4.0.1 > mquery@1.4.0 > debug@0.7.4
• Introduced through: npm-check@4.0.1 > mocha@2.5.3 > debug@2.2.0

Overview

debug is a JavaScript debugging utility modelled after Node.js core's debugging technique..

debug uses printf-style formatting. Affected versions of this package are vulnerable to Regular expression Denial of Service (ReDoS) attacks via the the %o formatter (Pretty-print an Object all on a single line). It used a regular expression (/\s*\n\s*/g) in order to strip whitespaces and replace newlines with spaces, in order to join the data into a single line. This can cause a very low impact of about 2 seconds matching time for data 50k characters long.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

• A The string must start with the letter 'A'
• (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
• D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

1. CCC
2. CC+C
3. C+CC
4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade debug to version 2.6.9, 3.1.0 or higher.

References

• GitHub Issue
• GitHub PR

• Vulnerable module: ms
• Introduced through: ms@0.1.0 and mocha@2.5.3

Detailed paths

• Introduced through: mongoose@4.0.1 > ms@0.1.0
• Introduced through: npm-check@4.0.1 > mocha@2.5.3 > debug@2.2.0 > ms@0.7.1

Overview

ms is a tiny millisecond conversion utility.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) due to an incomplete fix for previously reported vulnerability npm:ms:20151024. The fix limited the length of accepted input string to 10,000 characters, and turned to be insufficient making it possible to block the event loop for 0.3 seconds (on a typical laptop) with a specially crafted string passed to ms() function.

Proof of concept

ms = require('ms');
ms('1'.repeat(9998) + 'Q') // Takes about ~0.3s

Note: Snyk's patch for this vulnerability limits input length to 100 characters. This new limit was deemed to be a breaking change by the author. Based on user feedback, we believe the risk of breakage is very low, while the value to your security is much greater, and therefore opted to still capture this change in a patch for earlier versions as well. Whenever patching security issues, we always suggest to run tests on your code to validate that nothing has been broken.

For more information on Regular Expression Denial of Service (ReDoS) attacks, go to our blog.

Disclosure Timeline

• Feb 9th, 2017 - Reported the issue to package owner.
• Feb 11th, 2017 - Issue acknowledged by package owner.
• April 12th, 2017 - Fix PR opened by Snyk Security Team.
• May 15th, 2017 - Vulnerability published.
• May 16th, 2017 - Issue fixed and version 2.0.0 released.
• May 21th, 2017 - Patches released for versions >=0.7.1, <=1.0.0.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

• A The string must start with the letter 'A'
• (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
• D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

1. CCC
2. CC+C
3. C+CC
4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade ms to version 2.0.0 or higher.

References

• GitHub PR
• GitHub Commit

• Vulnerable module: deep-extend
• Introduced through: registry-url@2.1.0

Detailed paths

• Introduced through: npm-check@3.2.7 > registry-url@2.1.0 > rc@0.5.5 > deep-extend@0.2.11

Overview

Affected versions of deep-extend are vulnerable to Prototype Pollution. Utilities function in all the listed modules can be tricked into modifying the prototype of "Object" when the attacker control part of the structure passed to these function. This can let an attacker add or modify existing property that will exist on all object.

PoC by HoLyVieR

var merge = require('deep-extend');
var malicious_payload = '{"__proto__":{"oops":"It works !"}}';

var a = {};
console.log("Before : " + a.oops);
merge({}, JSON.parse(malicious_payload));
console.log("After : " + a.oops);

Remediation

Upgrade deep-extend to version 0.5.1 or higher.

References

• HackerOne Report
• GitHub Commit
• GitHub PR
• GitHub Issue

• Vulnerable module: hoek
• Introduced through: npm@6.2.0, npm@6.2.0 and others

Detailed paths

• Introduced through: browserify@0.0.3 > npm@6.2.0 > libcipm@2.0.0 > npm-lifecycle@2.0.3 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > hoek@2.16.3
• Introduced through: browserify@0.0.3 > npm@6.2.0 > npm-lifecycle@2.0.3 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > hoek@2.16.3
• Introduced through: browserify@0.0.3 > npm@6.2.0 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > hoek@2.16.3
• Introduced through: browserify@0.0.3 > npm@6.2.0 > libcipm@2.0.0 > npm-lifecycle@2.0.3 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > boom@2.10.1 > hoek@2.16.3
• Introduced through: browserify@0.0.3 > npm@6.2.0 > npm-lifecycle@2.0.3 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > boom@2.10.1 > hoek@2.16.3
• Introduced through: browserify@0.0.3 > npm@6.2.0 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > boom@2.10.1 > hoek@2.16.3
• Introduced through: browserify@0.0.3 > npm@6.2.0 > libcipm@2.0.0 > npm-lifecycle@2.0.3 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > cryptiles@2.0.5 > boom@2.10.1 > hoek@2.16.3
• Introduced through: browserify@0.0.3 > npm@6.2.0 > npm-lifecycle@2.0.3 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > cryptiles@2.0.5 > boom@2.10.1 > hoek@2.16.3
• Introduced through: browserify@0.0.3 > npm@6.2.0 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > cryptiles@2.0.5 > boom@2.10.1 > hoek@2.16.3
• Introduced through: browserify@0.0.3 > npm@6.2.0 > libcipm@2.0.0 > npm-lifecycle@2.0.3 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > sntp@1.0.9 > hoek@2.16.3
• Introduced through: browserify@0.0.3 > npm@6.2.0 > npm-lifecycle@2.0.3 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > sntp@1.0.9 > hoek@2.16.3
• Introduced through: browserify@0.0.3 > npm@6.2.0 > node-gyp@3.7.0 > request@2.81.0 > hawk@3.1.3 > sntp@1.0.9 > hoek@2.16.3
• Introduced through: npm-check@0.0.3 > npm@1.4.29 > request@2.42.0 > hawk@1.1.1 > hoek@0.9.1
• Introduced through: npm-check@0.0.3 > npm@1.4.29 > request@2.42.0 > hawk@1.1.1 > boom@0.4.2 > hoek@0.9.1
• Introduced through: npm-check@0.0.3 > npm@1.4.29 > request@2.42.0 > hawk@1.1.1 > cryptiles@0.2.2 > boom@0.4.2 > hoek@0.9.1
• Introduced through: npm-check@0.0.3 > npm@1.4.29 > request@2.42.0 > hawk@1.1.1 > sntp@0.2.4 > hoek@0.9.1

Overview

hoek is a Utility methods for the hapi ecosystem.

Affected versions of this package are vulnerable to Prototype Pollution. The utilities function allow modification of the Object prototype. If an attacker can control part of the structure passed to this function, they could add or modify an existing property.

PoC by Olivier Arteau (HoLyVieR)

var Hoek = require('hoek');
var malicious_payload = '{"__proto__":{"oops":"It works !"}}';

var a = {};
console.log("Before : " + a.oops);
Hoek.merge({}, JSON.parse(malicious_payload));
console.log("After : " + a.oops);

Remediation

Upgrade hoek to versions 4.2.1, 5.0.3 or higher.

References

• HackerOne Report
• GitHub PR
• GitHub Issue - 4.2.1 Backport
• GitHub Commit 5.0.3
• GitHub Commit 4.2.x

• Vulnerable module: hawk
• Introduced through: npm@1.4.29

Detailed paths

• Introduced through: npm-check@0.0.3 > npm@1.4.29 > request@2.42.0 > hawk@1.1.1

Overview

hawk is an HTTP authentication scheme using a message authentication code (MAC) algorithm to provide partial HTTP request cryptographic verification.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) attacks.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

• A The string must start with the letter 'A'
• (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
• D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

1. CCC
2. CC+C
3. C+CC
4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

You can read more about Regular Expression Denial of Service (ReDoS) on our blog.

References

• GitHub Issue

• Vulnerable module: mime
• Introduced through: express@3.0.6, express@3.0.6 and others

Detailed paths

• Introduced through: cordova@0.0.3 > express@3.0.6 > connect@2.7.2 > send@0.1.0 > mime@1.2.6
• Introduced through: cordova@0.0.3 > express@3.0.6 > send@0.1.0 > mime@1.2.6
• Introduced through: hapi@0.0.3 > express@2.5.11 > mime@1.2.4
• Introduced through: angular@0.0.3 > express@2.5.10 > mime@1.2.4
• Introduced through: npm-check@0.0.3 > npm@1.4.29 > request@2.42.0 > form-data@0.1.4 > mime@1.2.11

Overview

mime is a comprehensive, compact MIME type module.

Affected versions of this package are vulnerable to Regular expression Denial of Service (ReDoS). It uses regex the following regex /.*[\.\/\\]/ in its lookup, which can cause a slowdown of 2 seconds for 50k characters.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Many Regular Expression implementations may reach extreme situations that cause them to work very slowly (exponentially related to input size), allowing an attacker to exploit this and can cause the program to enter these extreme situations by using a specially crafted input and cause the service to excessively consume CPU, resulting in a Denial of Service.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

• A The string must start with the letter 'A'
• (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
• D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

1. CCC
2. CC+C
3. C+CC
4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade mime to versions 1.4.1, 2.0.3 or higher.

References

• Github Issue
• Github Commit 1.x
• Github Commit 2.0.x