A privilege escalation vulnerability existed in the Below service prior to v0.9.0 due to the creation of a world-writable directory at /var/log/below. This could have allowed local unprivileged users to escalate to root privileges through symlink attacks that manipulate files such as /etc/shadow.
The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.
| Link | Tags |
|---|---|
| https://www.facebook.com/security/advisories/cve-2025-27591 | vendor advisory patch |
| https://github.com/facebookincubator/below/commit/da9382e6e3e332fd2c3195e22f34977f83f0f1f3 | patch |
| http://www.openwall.com/lists/oss-security/2025/03/12/1 | exploit mailing list |