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GHSA-7wwv-vh3v-89cq

ReDOS vulnerabities: multiple grammars

Medium npm
Severity
Medium
The publisher's own rating, not a CVSS score
Exploit chance (EPSS)
—
No score published
Known exploited
No
Not in CISA's catalog
Weakness
CWE-20 Improper Input Validation
CWE-400 Uncontrolled Resource Consumption
Fix
Available
2 packages have a fixed version

Description

Impact: Potential ReDOS vulnerabilities (exponential and polynomial RegEx backtracking)

oswasp:

The Regular expression Denial of Service (ReDoS) is a Denial of Service attack, that exploits the fact that most Regular Expression implementations may reach extreme situations that cause them to work very slowly (exponentially related to input size). An attacker can then cause a program using a Regular Expression to enter these extreme situations and then hang for a very long time.

If are you are using Highlight.js to highlight user-provided data you are possibly vulnerable. On the client-side (in a browser or Electron environment) risks could include lengthy freezes or crashes... On the server-side infinite freezes could occur... effectively preventing users from accessing your app or service (ie, Denial of Service).

This is an issue with grammars shipped with the parser (and potentially 3rd party grammars also), not the parser itself. If you are using Highlight.js with any of the following grammars you are vulnerable. If you are using highlightAuto to detect the language (and have any of these grammars registered) you are vulnerable. Exponential grammars (C, Perl, JavaScript) are auto-registered when using the common grammar subset/library require('highlight.js/lib/common') as of 10.4.0 - see https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@10.4.0/build/highlight.js

All versions prior to 10.4.1 are vulnerable, including version 9.18.5.

Grammars with exponential backtracking issues:

  • c-like (c, cpp, arduino)
  • handlebars (htmlbars)
  • gams
  • perl
  • jboss-cli
  • r
  • erlang-repl
  • powershell
  • routeros
  • livescript (10.4.0 and 9.18.5 included this fix)
  • javascript & typescript (10.4.0 included partial fixes)

And of course any aliases of those languages have the same issue. ie: hpp is no safer than cpp.

Grammars with polynomial backtracking issues:

  • kotlin
  • gcode
  • d
  • aspectj
  • moonscript
  • coffeescript/livescript
  • csharp
  • scilab
  • crystal
  • elixir
  • basic
  • ebnf
  • ruby
  • fortran/irpf90
  • livecodeserver
  • yaml
  • x86asm
  • dsconfig
  • markdown
  • ruleslanguage
  • xquery
  • sqf

And again: any aliases of those languages have the same issue. ie: ruby and rb share the same ruby issues.

Patches

  • Version 10.4.1 resolves these vulnerabilities. Please upgrade.

Workarounds / Mitigations

  • Discontinue use the affected grammars. (or perhaps use only those with poly vs exponential issues)
  • Attempt cherry-picking the grammar fixes into older versions...
  • Attempt using newer CDN versions of any affected languages. (ie using an older CDN version of the library with newer CDN grammars). Your mileage may vary.

References

For more information

If you have any questions or comments about this advisory:

Affected versions

npm

PackageVulnerableFixed in
@highlightjs/cdn-assets
< 10.4.1
10.4.1
highlight.js
>= 9.0.0, < 10.4.1
10.4.1

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

@highlightjs/cdn-assets npm → 10.4.1

npm
npm install @highlightjs/cdn-assets@10.4.1
yarn
yarn add @highlightjs/cdn-assets@10.4.1
pnpm
pnpm add @highlightjs/cdn-assets@10.4.1

highlight.js npm → 10.4.1

npm
npm install highlight.js@10.4.1
yarn
yarn add highlight.js@10.4.1
pnpm
pnpm add highlight.js@10.4.1

Weakness

CWE-20: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How to prevent it
  • Architecture and Design: Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses. [REF-1109] [REF-1110] [REF-1111]
  • Architecture and Design: Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Architecture and Design, Implementation: Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
  • Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
  • Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server. Even though client-side checks provide minimal benefits with respect to server-side security, they are still useful. First, they can support intrusion detection. If the server receives input that should have been rejected by the client, then it may be an indication of an attack. Second, client-side error-checking can provide helpful feedback to the user about the expectations for valid input. Third, there may be a reduction in server-side processing time for accidental input errors, although this is typically a small savings.
  • Implementation: When your application combines data from multiple sources, perform the validation after the sources have been combined. The individual data elements may pass the validation step but violate the intended restrictions after they have been combined.
  • Implementation: Be especially careful to validate all input when invoking code that crosses language boundaries, such as from an interpreted language to native code. This could create an unexpected interaction between the language boundaries. Ensure that you are not violating any of the expectations of the language with which you are interfacing. For example, even though Java may not be susceptible to buffer overflows, providing a large argument in a call to native code might trigger an overflow.
  • Implementation: Directly convert your input type into the expected data type, such as using a conversion function that translates a string into a number. After converting to the expected data type, ensure that the input's values fall within the expected range of allowable values and that multi-field consistencies are maintained.
  • Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180, CWE-181). Make sure that your application does not inadvertently decode the same input twice (CWE-174). Such errors could be used to bypass allowlist schemes by introducing dangerous inputs after they have been checked. Use libraries such as the OWASP ESAPI Canonicalization control. Consider performing repeated canonicalization until your input does not change any more. This will avoid double-decoding and similar scenarios, but it might inadvertently modify inputs that are allowed to contain properly-encoded dangerous content.
  • Implementation: When exchanging data between components, ensure that both components are using the same character encoding. Ensure that the proper encoding is applied at each interface. Explicitly set the encoding you are using whenever the protocol allows you to do so.

CWE-400: Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

How to prevent it
  • Architecture and Design: Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
  • Architecture and Design: Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
  • Architecture and Design: Ensure that protocols have specific limits of scale placed on them.
  • Implementation: Ensure that all failures in resource allocation place the system into a safe posture.

References

Other links

Timeline

  1. Published
  2. Last updated by the source
AdvisorySeverityWhy it's related
GHSA-vfrc-7r7c-w9mx
Prototype Pollution in highlight.js
High Also affects highlight.js
GHSA-m665-v7pm-7grj
zip: Critical Parser Differential & Security Control Bypass via Dual-Header Inconsistencies (Zip Cloaking) Leading to Arbitrary File Overwrite & RCE
Critical Same weakness, CWE-20
GHSA-g5ff-637f-6q2m
LiteLLM: internal_user_viewer arbitrary local file read via `vertex_ai_credentials`
High Same weakness, CWE-20
GHSA-h3rc-j82p-2c3h
vLLM: Untrusted EPS inputs can trigger denial of service or Ghostscript RCE
High Same weakness, CWE-20
GHSA-8c8m-p3m8-cjg8
Nodemailer: A nested comment ends early in addressparser, releasing the rest of the comment as a recipient
Medium Same weakness, CWE-20
GHSA-m943-m63m-w62w
Nodemailer: A ";" inside a quoted string or comment ends an address group early in addressparser, turning display text into a recipient
Medium Same weakness, CWE-20
GHSA-85x2-q946-cp5h
Nodemailer: A ">" inside a quoted local part ends an angle-addr early in addressparser, delivering to a domain the header does not name
Medium Same weakness, CWE-20
GHSA-5hx5-vpf9-5wcv
pypdf: Unvalidated JPEG image data loading
Low Same weakness, CWE-20
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