Executive brief
Blamer is a Node.js utility for analyzing git blame information. Versions prior to 1.0.1 allow attackers to execute arbitrary system commands by injecting malicious arguments. An attacker with the ability to control input to the blamer tool can achieve complete system compromise, including reading sensitive files, modifying code, or launching further attacks.
Technical details
The vulnerability is a command injection flaw (CWE-78) in Blamer's argument handling, where special shell metacharacters in user-supplied arguments are not properly sanitized before being passed to OS command execution. An unauthenticated attacker on the network can supply crafted arguments to the blamer command to inject arbitrary shell commands. This requires no user interaction or authentication. The vulnerability was fixed in version 1.0.1, which was released on 2020-03-09 as part of a rewrite that included proper security hardening of script execution.
Affected products
- Blamer blamer 0 to 1.0.0
Timeline
- 2020-03-11: disclosed
- 2020-03-09: patched: Version 1.0.1 released with security fix
- 2022-05-24: advisory