Horizon Alert
Summary of the vulnerability and why it matters
A file descriptor can be closed while a thread is waiting for it, leading to the object being freed while the thread remains blocked. This scenario can result in a use-after-free vulnerability. The vulnerability can be exploited by an unprivileged local user to gain elevated privileges.
- Vulnerable kernel component
- Use-after-free memory access
- Unauthorized privilege escalation
Attack Path
How an attacker could exploit the issue
A race condition allows a local user to trigger a use-after-free vulnerability. This occurs when a file descriptor is closed while a thread is waiting on it, leading to the thread accessing freed memory. Exploiting this can allow an unprivileged local user to gain superuser privileges.
- Local user with system access
- Close file descriptor while thread waits
- Access freed memory, gain elevated privileges
Live Threat
Current exploitation, exposure, and threat context
A use-after-free vulnerability has been identified in the operating system that could allow an unprivileged local user to gain superuser privileges. This type of vulnerability occurs when a program attempts to access memory that has already been freed, potentially leading to system instability or unauthorized access. The root cause involves a race condition where a file descriptor can be closed while a thread is waiting on it, leading to the thread accessing deallocated memory.
- Attacker needs low skill.
- Local access required to exploit.
- High business risk; treat as urgent.
Priority actions
Operational Fix
Recommended remediation, mitigation, and detection steps
A use-after-free vulnerability has been identified that may allow an unprivileged local user to gain superuser privileges. This occurs when a file descriptor is closed while a thread is waiting on that descriptor, potentially leading to memory access issues. The risk is classified as internal due to the local access requirement.
- Find affected assets.
- Reduce exposure or isolate risk.
- Fix, verify, and monitor.
