Incorrect permission assignment in Meta Platforms below
Priority LOW 32CWE-732Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and GitHub.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00372 31st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed below (Meta Platforms, Inc): 0.9.0below (crates.io): 0.9.0
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Meta Platforms | below | 0.0.0 to before 0.9.0 | 0.9.0 | Patch available | CNA |
| — | below (crates.io) | before 0.9.0 | 0.9.0 | Patch available | GHSA-9mc5-7qhg-fp3w |
- below VendorMeta Platforms Affected 0.0.0 to before 0.9.0 Fixed in 0.9.0 Patch available CNA
- below (crates.io) Vendor— Affected before 0.9.0 Fixed in 0.9.0 Patch available GHSA-9mc5-7qhg-fp3w
Remediation
- Fix · CNA below (Meta Platforms, Inc) Fixed in 0.9.0
- Fix · GHSA-9mc5-7qhg-fp3w below (crates.io) Fixed in 0.9.0 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2025-27591
- 2026-10-03 Alias added: GHSA-9mc5-7qhg-fp3w
References
Patch 2
Other 5
- https://github.com/facebookincubator/below/security/advisories/GHSA-9mc5-7qhg-fp3w
- https://github.com/facebookincubator/below/commit/10e73a21d67baa2cd613ee92ce999cda145e1a83
- https://github.com/facebookincubator/below
- https://rustsec.org/advisories/RUSTSEC-2025-0149.html
- https://www.openwall.com/lists/oss-security/2025/03/12/1
More Meta Platforms vulnerabilities
- TI-2025-34672 An integer overflow vulnerability in the loading of ExecuTorch models can cause… CVSS 3.1CRITICAL 9.8
- TI-2025-34671 Heap-based buffer overflow in Meta Platforms ExecuTorch CVSS 3.1CRITICAL 9.8
- TI-2025-34670 Out-of-bounds read in Meta Platforms ExecuTorch CVSS 3.1CRITICAL 9.8
- TI-2025-34669 Heap-based buffer overflow in Meta Platforms ExecuTorch CVSS 3.1CRITICAL 9.8
- TI-2025-21707 Integer overflow in Meta Platforms ExecuTorch CVSS 3.1CRITICAL 9.8
- TI-2025-21706 Integer overflow in Meta Platforms ExecuTorch CVSS 3.1CRITICAL 9.8
Sources
- CVE-2025-27591 · CVE Program
- CVE-2025-27591 · NVD
- FIRST EPSS
- GHSA-9mc5-7qhg-fp3w · GitHub Advisory Database · CC BY 4.0
- CVE-2025-27591 · Red Hat security data · CC BY 4.0
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