Github : Security Vulnerabilities, CVEs, Published In 2023

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed issue comments to be read with an improperly scoped token. This vulnerability affected all versions of GitHub Enterprise Server since 3.7 and was fixed in version 3.17.19, 3.8.12, 3.9.7, 3.10.4, and 3.11.1. 

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed issue comments to be updated with an improperly scoped token. This vulnerability did not allow unauthorized access to any repository content as it also required contents:write and issues:read permissions. This vulnerability affected all versions of GitHub Enterprise Server since 3.7 and was fixed in version 3.17.19, 3.8.12, 3.9.7, 3.10.4, and 3.11.1. 

A race condition in GitHub Enterprise Server was identified that could allow an attacker administrator access. To exploit this, an organization needs to be converted from a user. This vulnerability affected all versions of GitHub Enterprise Server since 3.7 and was fixed in version 3.7.19, 3.8.12, 3.9.7, 3.10.4, and 3.11.1. 

An insufficient entropy vulnerability was identified in GitHub Enterprise Server (GHES) that allowed an attacker to brute force a user invitation to the GHES Management Console. To exploit this vulnerability, an attacker would need knowledge that a user invitation was pending. This vulnerability affected all versions of GitHub Enterprise Server since 3.8 and was fixed in version 3.8.12, 3.9.7, 3.10.4, and 3.11.1. This vulnerability was reported via the GitHub Bug Bounty program.

Improper privilege management in all versions of GitHub Enterprise Server allows users with authorized access to the management console with an editor role to escalate their privileges by making requests to the endpoint used for bootstrapping the instance. This vulnerability affected GitHub Enterprise Server version 3.8.0 and above and was fixed in version 3.8.12, 3.9.6, 3.10.3, and 3.11.0.

Improper access control in all versions of GitHub Enterprise Server allows unauthorized users to view private repository names via the "Get a check run" API endpoint. This vulnerability did not allow unauthorized access to any repository content besides the name. This vulnerability affected GitHub Enterprise Server version 3.7.0 and above and was fixed in version 3.17.19, 3.8.12, 3.9.7 3.10.4, and 3.11.0.

A path traversal vulnerability was identified in GitHub Enterprise Server that allowed arbitrary file reading when building a GitHub Pages site. To exploit this vulnerability, an attacker would need permission to create and build a GitHub Pages site on the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server since 3.7 and was fixed in version 3.7.19, 3.8.12, 3.9.7, 3.10.4, and 3.11.1. This vulnerability was reported via the GitHub Bug Bounty program.

cmark-gfm is an extended version of the C reference implementation of CommonMark, a rationalized version of Markdown syntax with a spec. Three polynomial time complexity issues in cmark-gfm may lead to unbounded resource exhaustion and subsequent denial of service. These vulnerabilities have been patched in 0.29.0.gfm.12.

Visual Studio Code GitHub Pull Requests and Issues Extension Remote Code Execution Vulnerability

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. A polynomial time complexity issue in cmark-gfm may lead to unbounded resource exhaustion and subsequent denial of service. This CVE covers quadratic complexity issues when parsing text which leads with either large numbers of `_` characters. This issue has been addressed in version 0.29.0.gfm.10. Users are advised to upgrade. Users unable to upgrade should validate that their input comes from trusted sources. ### Impact A polynomial time complexity issue in cmark-gfm may lead to unbounded resource exhaustion and subsequent denial of service. ### Proof of concept ``` $ ~/cmark-gfm$ python3 -c 'pad = "_" * 100000; print(pad + "." + pad, end="")' | time ./build/src/cmark-gfm --to plaintext ``` Increasing the number 10000 in the above commands causes the running time to increase quadratically. ### Patches This vulnerability have been patched in 0.29.0.gfm.10. ### Note on cmark and cmark-gfm XXX: TBD [cmark-gfm](https://github.com/github/cmark-gfm) is a fork of [cmark](https://github.com/commonmark/cmark) that adds the GitHub Flavored Markdown extensions. The two codebases have diverged over time, but share a common core. These bugs affect both `cmark` and `cmark-gfm`. ### Credit We would like to thank @gravypod for reporting this vulnerability. ### References https://en.wikipedia.org/wiki/Time_complexity ### For more information If you have any questions or comments about this advisory: * Open an issue in [github/cmark-gfm](https://github.com/github/cmark-gfm)

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. A polynomial time complexity issue in cmark-gfm may lead to unbounded resource exhaustion and subsequent denial of service. This CVE covers quadratic complexity issues when parsing text which leads with either large numbers of `>` or `-` characters. This issue has been addressed in version 0.29.0.gfm.10. Users are advised to upgrade. Users unable to upgrade should validate that their input comes from trusted sources.

Incorrect Permission Assignment for Critical Resource in GitHub Enterprise Server that allowed local operating system user accounts to read MySQL connection details including the MySQL password via configuration files. This vulnerability affected all versions of GitHub Enterprise Server and was fixed in versions 3.7.18, 3.8.11, 3.9.6, and 3.10.3.

An incorrect comparison vulnerability was identified in GitHub Enterprise Server that allowed commit smuggling by displaying an incorrect diff in a re-opened Pull Request. To do so, an attacker would need write access to the repository. This vulnerability affected all versions of GitHub Enterprise Server and was fixed in versions 3.6.17, 3.7.15, 3.8.8, 3.9.3, and 3.10.1. This vulnerability was reported via the GitHub Bug Bounty program.

An incorrect comparison vulnerability was identified in GitHub Enterprise Server that allowed commit smuggling by displaying an incorrect diff in a re-opened Pull Request. To exploit this vulnerability, an attacker would need write access to the repository. This vulnerability was reported via the GitHub Bug Bounty Program https://bounty.github.com/ .

An incorrect comparison vulnerability was identified in GitHub Enterprise Server that allowed commit smuggling by displaying an incorrect diff within the GitHub pull request UI. To do so, an attacker would need write access to the repository. This vulnerability affected GitHub Enterprise Server versions 3.7.0 and above and was fixed in versions 3.7.9, 3.8.2, and 3.9.1. This vulnerability was reported via the GitHub Bug Bounty program.

An authorization/sensitive information disclosure vulnerability was identified in GitHub Enterprise Server that allowed a fork to retain read access to an upstream repository after its visibility was changed to private. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.10.0 and was fixed in versions 3.9.4, 3.8.9, 3.7.16 and 3.6.18. This vulnerability was reported via the GitHub Bug Bounty program.

An incorrect comparison vulnerability was identified in GitHub Enterprise Server that allowed commit smuggling by displaying an incorrect diff. To do so, an attacker would need write access to the repository and be able to correctly guess the target branch before it’s created by the code maintainer. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.9 and was fixed in versions 3.4.18, 3.5.15, 3.6.11, 3.7.8, and 3.8.1. This vulnerability was reported via the GitHub Bug Bounty program.

An improper authentication vulnerability was identified in GitHub Enterprise Server that allowed an unauthorized actor to modify other users' secret gists by authenticating through an SSH certificate authority. To do so, a user had to know the secret gist's URL. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.9 and was fixed in versions 3.4.18, 3.5.15, 3.6.11, 3.7.8, and 3.8.1. This vulnerability was reported via the GitHub Bug Bounty program.

A path traversal vulnerability was identified in GitHub Enterprise Server that allowed remote code execution when building a GitHub Pages site. To exploit this vulnerability, an attacker would need permission to create and build a GitHub Pages site on the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to versions 3.8 and was fixed in versions 3.7.7, 3.6.10, 3.5.14, and 3.4.17. This vulnerability was reported via the GitHub Bug Bounty program.

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. Versions prior to 0.29.0.gfm.7 contain a polynomial time complexity issue in handle_close_bracket that may lead to unbounded resource exhaustion and subsequent denial of service. This vulnerability has been patched in 0.29.0.gfm.7.

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. In versions prior 0.29.0.gfm.7, a crafted markdown document can trigger an out-of-bounds read in the `validate_protocol` function. We believe this bug is harmless in practice, because the out-of-bounds read accesses `malloc` metadata without causing any visible damage.This vulnerability has been patched in 0.29.0.gfm.7.

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. Versions prior to 0.29.0.gfm.7 are subject to a polynomial time complexity issue in cmark-gfm that may lead to unbounded resource exhaustion and subsequent denial of service. This vulnerability has been patched in 0.29.0.gfm.7.

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. Versions prior to 0.29.0.gfm.7 are subject to several polynomial time complexity issues in cmark-gfm that may lead to unbounded resource exhaustion and subsequent denial of service. Various commands, when piped to cmark-gfm with large values, cause the running time to increase quadratically. These vulnerabilities have been patched in version 0.29.0.gfm.7.

A code injection vulnerability was identified in GitHub Enterprise Server that allowed setting arbitrary environment variables from a single environment variable value in GitHub Actions when using a Windows based runner. To exploit this vulnerability, an attacker would need existing permission to control the value of environment variables for use with GitHub Actions. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.8.0 and was fixed in versions 3.4.15, 3.5.12, 3.6.8, 3.7.5. This vulnerability was reported via the GitHub Bug Bounty program.

A path traversal vulnerability was identified in GitHub Enterprise Server that allowed arbitrary file reading when building a GitHub Pages site. To exploit this vulnerability, an attacker would need permission to create and build a GitHub Pages site on the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server since 3.7 and was fixed in version 3.7.6. This vulnerability was reported via the GitHub Bug Bounty program.