gulp-jshint (latest)
Published 04 Mar, 2018
No known vulnerabilities in gulp-jshint
Security wise, gulp-jshint seems to be a safe package to use.
Over time, new vulnerabilities may be disclosed on gulp-jshint and other packages. To easily find, fix and prevent such vulnerabilties, protect your repos with Snyk!
Vulnerable versions of gulp-jshint
Fixed in 2.0.3
Prototype Pollution
Detailed paths
- Introduced through: yo@2.0.2 > insight@0.8.4 > inquirer@0.10.1 > lodash@3.10.1
- Introduced through: sequelize@2.0.2 > lodash@2.4.2
- Introduced through: gulp-jshint@2.0.2 > rcloader@0.1.2 > lodash@2.4.2
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
Fixed in 2.0.2
Regular Expression Denial of Service (DoS)
Detailed paths
- Introduced through: gulp@2.0.1 > gaze@0.4.2 > globule@0.1.0 > minimatch@0.2.14
- Introduced through: gulp@2.0.1 > gaze@0.4.2 > globule@0.1.0 > glob@3.1.21 > minimatch@0.2.14
- Introduced through: mocha@2.0.1 > glob@3.2.3 > minimatch@0.2.14
- Introduced through: browser-sync@2.0.1 > foxy@9.0.0 > resp-modifier@2.1.0 > minimatch@2.0.10
- Introduced through: browser-sync@2.0.1 > resp-modifier@2.1.0 > minimatch@2.0.10
- Introduced through: browser-sync@2.0.1 > glob-watcher@0.0.7 > gaze@0.5.2 > globule@0.1.0 > minimatch@0.2.14
- Introduced through: browser-sync@2.0.1 > glob-watcher@0.0.7 > gaze@0.5.2 > globule@0.1.0 > glob@3.1.21 > minimatch@0.2.14
- Introduced through: jshint@2.0.1 > minimatch@0.4.0
- Introduced through: gulp-jshint@2.0.1 > minimatch@2.0.10
Overview
minimatch
is a minimalistic matching library used for converting glob expressions into JavaScript RegExp objects.
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) attacks.
The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Many Regular Expression implementations may reach edge cases that causes 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.
An attacker can provide a long value to the minimatch
function, which nearly matches the pattern being matched. This will cause the regular expression matching to take a long time, all the while occupying the event loop and preventing it from processing other requests and making the server unavailable (a Denial of Service attack).
You can read more about Regular Expression Denial of Service (ReDoS)
on our blog.
Remediation
Upgrade minimatch
to version 3.0.2
or greater.
References
Fixed in 2.0.0
Command Injection
Detailed paths
- Introduced through: gulp-jshint@1.12.0 > jshint@2.9.6 > shelljs@0.3.0
Overview
shelljs
is a portable Unix shell commands for Node.js.
Affected version of this package are vulnerable to Command Injection. It is possible to invoke commands from shell.exec()
from external sources, allowing an attacker to inject arbitrary commands.
Remediation
There is no fix version for shelljs
.
References
Fixed in 1.5.5
Regular Expression Denial of Service (DoS)
Detailed paths
- Introduced through: browser-sync@1.5.4 > connect@3.2.0 > debug@2.0.0 > ms@0.6.2
- Introduced through: browser-sync@1.5.4 > connect@3.2.0 > finalhandler@0.2.0 > debug@2.0.0 > ms@0.6.2
- Introduced through: browser-sync@1.5.4 > socket.io@1.1.0 > engine.io@1.4.0 > debug@1.0.3 > ms@0.6.2
- Introduced through: gulp-jshint@1.5.4 > mocha@1.21.5 > debug@2.0.0 > ms@0.6.2
Overview
ms
is a tiny milisecond conversion utility.
Affected versions of this package are vulnerable to a Regular expression Denial of Service (ReDoS) attack when converting a time period string (i.e. "2 days"
, "1h"
) into milliseconds integer. A malicious user could pas extremely long strings to ms()
, causing the server take a long time to process, subsequently blocking the event loop for that extended period.
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:
- CCC
- CC+C
- C+CC
- 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.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
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 0.7.1.
If direct dependency upgrade is not possible, use snyk wizard to patch this vulnerability.
References
Regular Expression Denial of Service (ReDoS)
Detailed paths
- Introduced through: browser-sync@1.5.4 > connect@3.2.0 > debug@2.0.0
- Introduced through: browser-sync@1.5.4 > connect@3.2.0 > finalhandler@0.2.0 > debug@2.0.0
- Introduced through: browser-sync@1.5.4 > localtunnel@1.9.0 > debug@2.6.8
- Introduced through: browser-sync@1.5.4 > socket.io@1.1.0 > debug@0.7.4
- Introduced through: browser-sync@1.5.4 > socket.io@1.1.0 > socket.io-parser@2.2.1 > debug@0.7.4
- Introduced through: browser-sync@1.5.4 > socket.io@1.1.0 > socket.io-client@1.1.0 > debug@0.7.4
- Introduced through: browser-sync@1.5.4 > socket.io@1.1.0 > socket.io-client@1.1.0 > engine.io-client@1.4.0 > debug@0.7.4
- Introduced through: browser-sync@1.5.4 > socket.io@1.1.0 > socket.io-client@1.1.0 > socket.io-parser@2.2.2 > debug@0.7.4
- Introduced through: browser-sync@1.5.4 > socket.io@1.1.0 > socket.io-adapter@0.2.0 > debug@0.7.4
- Introduced through: browser-sync@1.5.4 > socket.io@1.1.0 > socket.io-adapter@0.2.0 > socket.io-parser@2.1.2 > debug@0.7.4
- Introduced through: browser-sync@1.5.4 > socket.io@1.1.0 > engine.io@1.4.0 > debug@1.0.3
- Introduced through: gulp-jshint@1.5.4 > mocha@1.21.5 > debug@2.0.0
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:
- CCC
- CC+C
- C+CC
- 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.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
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
Regular Expression Denial of Service (ReDoS)
Detailed paths
- Introduced through: browser-sync@1.5.4 > connect@3.2.0 > debug@2.0.0 > ms@0.6.2
- Introduced through: browser-sync@1.5.4 > connect@3.2.0 > finalhandler@0.2.0 > debug@2.0.0 > ms@0.6.2
- Introduced through: browser-sync@1.5.4 > socket.io@1.1.0 > engine.io@1.4.0 > debug@1.0.3 > ms@0.6.2
- Introduced through: gulp-jshint@1.5.4 > mocha@1.21.5 > debug@2.0.0 > ms@0.6.2
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:
- CCC
- CC+C
- C+CC
- 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.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
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
Arbitrary Code Injection
Detailed paths
- Introduced through: gulp-jshint@1.5.4 > mocha@1.21.5 > growl@1.8.1
Overview
growl
is a package adding Growl support for Nodejs.
Affected versions of the package are vulnerable to Arbitrary Code Injection due to unsafe use of the eval()
function. Node.js provides the eval()
function by default, and is used to translate strings into Javascript code. An attacker can craft a malicious payload to inject arbitrary commands.
Remediation
Upgrade growl
to version 1.10.0 or higher.
References
Fixed in 1.5.2
Insecure use of /tmp folder
Detailed paths
- Introduced through: gulp-jshint@1.5.1 > jshint@2.4.4 > cli@0.4.5
Overview
cli
is an npm package used for rapidly building command line apps.
When used in daemon
mode, the library makes insecure use of two files in the /tmp/
folder: /tmp/<app-name>.pid
and /tmp/<app-name>.log
. These allow an attacker to overwrite files they typically cannot access, but that are accessible by the user running the CLI-using app. This is possible since the /tmp/
folder is (typically) writeable to all system users, and because the names of the files in question are easily predicted by an attacker.
Note that while this is a real vulnerability, it relies on functionality (daemon
mode) which is only supported in very old Node versions (0.8 or older), and so is unlikely to be used by most cli
users. To avoid any doubt, the fixed version (1.0.0) removes support for this feature entirely.
Details
For example, assume user victim occasionally runs a CLI tool called cli-tool
, which uses the cli
package.
If an attacker gains write access to the /tmp/
folder of that machine (but not the higher permissions victim has), they can create the symbolic link /tmp/cli-tool.pid -> /home/victim/important-file
. When victim runs cli-tool
, the important-file
in victim's root directory will be nullified. If the CLI tool is run as root, the same can be done to nullify /etc/passwd
and make the system unbootable.
Note that popular CLI tools have no reason to mask their names, and so attackers can easily guess a long list of tools victims may run by checking the cli
package dependents.
Remediation
Upgrade cli
to version 1.0.0
or greater, which disables the affected feature.
From the fix release notes:
This feature relies on a beta release (e.g. version 0.5.1) of a Node.js
module on npm--one that was superseded by a stable (e.g. version 1.0)
release published three years ago [2]. Due to a build-time dependency on
the long-since deprecated `node-waf` tool, the module at that version
can only be built for Node.js versions 0.8 and below.
Given this, actual usage of this feature is likely very limited. Remove
it completely so the integrity of this module's core functionality can
be verified.
References
[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=809252 [2] https://github.com/node-js-libs/cli/commit/fd6bc4d2a901aabe0bb6067fbcc14a4fe3faa8b9