gh is GitHub’s official command line tool. From 1.6.0 to before 2.92.0, a security vulnerability has been identified in GitHub CLI that could allow terminal escape sequence injection when users view GitHub Actions workflow logs using gh run view –log or gh run view –log-failed. The vulnerability stems from the way GitHub CLI handles raw Actions log output. The gh run view –log and gh run view –log-failed commands stream workflow log lines to stdout or the configured pager without sanitizing terminal control sequences. An attacker who can influence GitHub Actions log content, for example via a PR triggered workflow, can embed escape sequences that are replayed in the users terminal when they inspect the run. Depending on the victims terminal emulator, injected sequences could change the window title, manipulate on screen content, or in some terminal emulators (such as screen) potentially execute arbitrary commands. This vulnerability is fixed in 2.92.0.
Weakness
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as escape, meta, or control character sequences when they are sent to a downstream component.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Cli | Github | 1.6.0 (including) | 2.92.0 (excluding) |
Potential Mitigations
- 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.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/134.html
- https://cwe.mitre.org/data/definitions/41.html
- https://cwe.mitre.org/data/definitions/81.html
- https://cwe.mitre.org/data/definitions/93.html