Horizon Alert
Summary of the vulnerability and why it matters
The libcap component contains a flaw that can be exploited by a local unprivileged user. This vulnerability allows an attacker with write access to a parent directory to manipulate file capabilities on unintended executables. The core issue involves a race condition within the `cap_set_file()` function.
- libcap's `cap_set_file()` function
- Time-of-check-to-time-of-use race condition
- Privilege escalation and unauthorized access
Attack Path
How an attacker could exploit the issue
This vulnerability allows a local, unprivileged user to escalate their privileges by manipulating file capabilities. An attacker with write access to a parent directory can exploit a race condition to redirect capability updates to a file they control. This redirection can result in unauthorized capabilities being added to, or legitimate capabilities being removed from, critical executables. Such an alteration could allow the attacker to execute commands with elevated privileges, impacting the integrity and security of the affected system.
- Local user needs write access.
- Attacker redirects capability updates.
- Privileges are escalated.
Live Threat
Current exploitation, exposure, and threat context
A vulnerability exists in libcap that could allow a local, unprivileged user to escalate their privileges. This is achieved by exploiting a race condition, enabling an attacker with write access to a parent directory to manipulate file capabilities on unintended executables. This could lead to unauthorized privilege elevation within the affected system.
- Attacker skill: Moderate.
- Required access: Local, write access to parent directory.
- Business risk: Potential for privilege escalation.
Priority actions
Operational Fix
Recommended remediation, mitigation, and detection steps
A vulnerability in libcap allows a local, unprivileged user to escalate privileges. This occurs through a race condition in the `cap_set_file()` function, enabling an attacker with write access to a parent directory to manipulate file capabilities on unintended executables. This could lead to the injection or removal of critical capabilities, significantly impacting system security.
- Identify systems with libcap.
- Restrict write access to parent directories.
- Apply vendor fixes and verify.
- Monitor for related system changes.
