Raw vector
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2025-27791 is a high-severity Relative Path Traversal (CWE-23) vulnerability. Its CVSS base score is 8.3 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 40th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and AC-3 (Access Enforcement) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
Collabora Online, a collaborative online office suite based on LibreOffice technology, is affected by a path traversal vulnerability in versions prior to 24.04.12.4, 23.05.19, and 22.05.25. The flaw resides in the handling of the CheckFileInfo BaseFileName field returned from WOPI servers and is tracked as CWE-23. It permits an arbitrary file write to any location writable by the Collabora Online process UID when a malicious WOPI server supplies the response, and the issue is compounded by a Time-of-Check/Time-of-Use DNS resolution weakness for attacker-controlled WOPI hostnames.
An unauthenticated attacker who can influence or supply a malicious WOPI server response can exploit the combined flaws to write files on the target system. Successful exploitation requires the Collabora Online instance to contact the attacker-controlled WOPI endpoint, after which the path traversal allows placement of attacker-chosen content at arbitrary filesystem locations reachable by the service UID, resulting in high integrity impact and limited availability impact per the CVSS 8.3 rating.
The referenced GitHub Security Advisory GHSA-9j32-gg3j-8w25 and the vendor patches indicate that the issue has been resolved in Collabora Online releases 24.04.13.1, 23.05.19, and 22.05.25. The EPSS score remains flat at a low value of 0.0116 with no material increase observed after disclosure.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-14833
Vulnerability Data
Collabora Online is a collaborative online office suite based on LibreOffice technology. In versions prior to 24.04.12.4, 23.05.19, and 22.05.25, there is a path traversal flaw in handling the CheckFileInfo BaseFileName field returned from WOPI servers. This allows for a…
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file to be written anywhere the uid running Collabora Online can write, if such a response was supplied by a malicious WOPI server. By combining this flaw with a Time of Check, Time of Use DNS lookup issue with a WOPI server address under attacker control, it is possible to present such a response to be processed by a Collabora Online instance. This issue has been patched in versions 24.04.13.1, 23.05.19, and 22.05.25.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Explicit validation of path inputs stops .. sequences from ever being interpreted by the file system.
Access enforcement directly blocks unauthorized file reads/writes that result from unresolved .. sequences.
Information-flow rules can be configured to reject traversals that would move data outside an approved directory boundary.
Least privilege reduces the set of reachable files even when a traversal succeeds.
Secure-engineering principles require safe pathname construction and input neutralization before any file operation.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require input validation and path sanitization that prevent relative traversal.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches path traversal via static/dynamic analysis, but does not itself implement the fix.
Secure coding standards require neutralizing path traversal sequences, directly addressing CWE-23.