Medium severity · published Mar 11, 2025
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
6.8
CVSS
0.4%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BE
Below · Facebook
before 0.9.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-27591
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-27591
Patch
https://github.com/facebookincubator/below/commit/da9382e6e3e332fd2c3195e22f34977f83f0f1f3
Patch
https://www.facebook.com/security/advisories/cve-2025-27591
Exploit
http://www.openwall.com/lists/oss-security/2025/03/12/1
