VulnerabilityAnalyzed

CVE-2025-27591

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.

MEDIUM 6.8EPSS 0.36%

Does this matter?

Lower severity and a low EPSS score (0.36%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1: 6.8 MEDIUMCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
EPSS: 0.36% probability · 30th percentile
CISA KEV: Not listed
Weakness: CWE-732
Affected: facebook/below
Source: cve-assign@fb.com

References

https://github.com/facebookincubator/below/commit/da9382e6e3e332fd2c3195e22f34977f83f0f1f3Patch
https://www.facebook.com/security/advisories/cve-2025-27591Patch, Vendor Advisory
http://www.openwall.com/lists/oss-security/2025/03/12/1Exploit, Mailing List

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.