GitHub Actions Runner vulnerable to Docker Command Escaping

GitHub Actions Runner is the application that runs a job from a GitHub Actions workflow. The actions runner invokes the docker cli directly in order to run job containers, service containers, or container actions. A bug in the logic for how the environment is encoded into these docker commands was discovered in versions prior to 2.296.2, 2.293.1, 2.289.4, 2.285.2, and 2.283.4 that allows an input to escape the environment variable and modify that docker command invocation directly. Jobs that use container actions, job containers, or service containers alongside untrusted user inputs in environment variables may be vulnerable. The Actions Runner has been patched, both on `github.com` and hotfixes for GHES and GHAE customers in versions 2.296.2, 2.293.1, 2.289.4, 2.285.2, and 2.283.4. GHES and GHAE customers may want to patch their instance in order to have their runners automatically upgrade to these new runner versions. As a workaround, users may consider removing any container actions, job containers, or service containers from their jobs until they are able to upgrade their runner versions.

Sensitive Information in Log File in GitHub Enterprise Server

An insertion of sensitive information into log file vulnerability was identified in the log files for a GitHub Enterprise Server back-end service that could permit an `adversary in the middle attack` when combined with other phishing techniques. To exploit this, an attacker would need access to the log files for the GitHub Enterprise Server appliance, a backup archive created with GitHub Enterprise Server Backup Utilities, or a service which received streamed logs. 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. 

Integer overflow in table parsing extension leads to heap memory corruption

cmark-gfm is GitHub's extended version of the C reference implementation of CommonMark. Prior to versions 0.29.0.gfm.3 and 0.28.3.gfm.21, an integer overflow in cmark-gfm's table row parsing `table.c:row_from_string` may lead to heap memory corruption when parsing tables who's marker rows contain more than UINT16_MAX columns. The impact of this heap corruption ranges from Information Leak to Arbitrary Code Execution depending on how and where `cmark-gfm` is used. If `cmark-gfm` is used for rendering remote user controlled markdown, this vulnerability may lead to Remote Code Execution (RCE) in applications employing affected versions of the `cmark-gfm` library. This vulnerability has been patched in the following cmark-gfm versions 0.29.0.gfm.3 and 0.28.3.gfm.21. A workaround is available. The vulnerability exists in the table markdown extensions of cmark-gfm. Disabling the table extension will prevent this vulnerability from being triggered.

Path traversal in GitHub Enterprise Server leading to remote code execution in GitHub Pages

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 instance. This vulnerability was fixed in versions 3.3.17, 3.4.12, 3.5.9, 3.6.5 and 3.7.2. This vulnerability was reported via the GitHub Bug Bounty program.

Incorrect authorization in GitHub Enterprise Server token generation leading to full admin access

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed a scoped user-to-server token to escalate to full admin/owner privileges. An attacker would require an account with admin access to install a malicious GitHub App. This vulnerability was fixed in versions 3.3.17, 3.4.12, 3.5.9, and 3.6.5. This vulnerability was reported via the GitHub Bug Bounty program.

The am function in lib/hub/commands.rb in hub before 1.12.1 allows local users to overwrite arbitrary files via a symlink attack on a temporary patch file.

Weberknecht, as used in GitHub Gaug.es and other products, does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.

GitHub Enterprise before 20120304 does not properly restrict the use of a hash to provide values for a model's attributes, which allows remote attackers to set the public_key[user_id] value via a modified URL for the public-key update form, related to a "mass assignment" vulnerability.

Incorrect Authorization in GitHub Enterprise Server leads to Action Workflow modifications without Workflow Scope

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed a repository-scoped token with read/write access to modify Action Workflow files without a Workflow scope. The Create or Update file contents API should enforce workflow scope. This vulnerability affected all versions of GitHub Enterprise Server prior to version 3.7 and was fixed in versions 3.3.16, 3.4.11, 3.5.8, and 3.6.4. This vulnerability was reported via the GitHub Bug Bounty program.

Incorrect authorization check in GitHub Enterprise Server leading to escalation of privileges in GraphQL API requests from GitHub Apps using scoped user-to-server tokens

An incorrect authorization vulnerability was identified in GitHub Enterprise Server, allowing for escalation of privileges in GraphQL API requests from GitHub Apps. This vulnerability allowed an app installed on an organization to gain access to and modify most organization-level resources that are not tied to a repository regardless of granted permissions, such as users and organization-wide projects. Resources associated with repositories were not impacted, such as repository file content, repository-specific projects, issues, or pull requests. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.7.1 and was fixed in versions 3.3.16, 3.4.11, 3.5.8, 3.6.4, 3.7.1. This vulnerability was reported via the GitHub Bug Bounty program.

Command injection vulnerability was identified in GitHub Enterprise Server that allowed privilege escalation in the Mangement Console

A command injection vulnerability was identified in GitHub Enterprise Server that allowed an attacker with an editor role in the Management Console to gain admin SSH access to the appliance via the actions-console docker container while setting a service URL. Exploitation of this vulnerability required access to the GitHub Enterprise Server instance and access to the Management Console with the editor role. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.12 and was fixed in versions 3.11.5, 3.10.7, 3.9.10, and 3.8.15. This vulnerability was reported via the GitHub Bug Bounty program.

Path traversal in GitHub Enterprise Server leading to arbitrary file reading when building a GitHub Pages site

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.

cmark-gfm Quadratic complexity bugs may lead to a denial of service

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.

Inefficient Quadratic complexity bug in handle_pointy_brace may lead to a denial of service

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 out-of-bounds read in validate_protocol

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 Quadratic complexity bug in handle_close_bracket may lead to a denial of service

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.

Information disclosure in GitHub Enterprise Server leading to unauthorized viewing of private repository names

An information disclosure vulnerability was identified in GitHub Enterprise Server that allowed private repositories to be added to a GitHub Actions runner group via the API by a user who did not have access to those repositories, resulting in the repository names being shown in the UI. To exploit this vulnerability, an attacker would need access to the GHES instance, permissions to modify GitHub Actions runner groups, and successfully guess the obfuscated ID of private repositories. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.7 and was fixed in versions 3.3.17, 3.4.12, 3.5.9, 3.6.5. This vulnerability was reported via the GitHub Bug Bounty program.

Code injection in GitHub Enterprise Server leading to arbitrary environment variables in GitHub Actions

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.

Path traversal in GitHub Enterprise Server leading to remote code execution

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.

Quadratic complexity may lead to a denial of service in 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 `_` 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)