OpenWrt: ACL bypass and arbitrary root file read via cgi-io cgi-download
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-22 and the CVSS impact.
Summary
OpenWrt is a Linux operating system targeting embedded devices. Prior to 25.12.5, the cgi-download handler in cgi-io authorizes the requested path against the caller's ubus session file ACL before canonicalization, and rpcd session.c uses fnmatch() without FNM_PATHNAME, allowing traversal such as an allowed wildcard prefix followed by ../ to read root-readable files including /etc/shadow. This vulnerability is fixed in 25.12.5.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA openwrt (openwrt) Fixed in 25.12.5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-62947
References
More Openwrt vulnerabilities
- TI-2024-13053 Improper input validation in MediaTek MT6890, MT7915, MT7916, MT7981, MT7986 CVSS 3.1CRITICAL 9.8
- TI-2026-44983 Cross-site scripting in openwrt CVSS 3.1CRITICAL 9.6
- TI-2026-40045 OpenWrt: EAD Integer Underflow → Pre-Auth Denial of Service CVSS 3.1MEDIUM 6.5
- TI-2023-09914 LuCI openwrt-22.03 branch git-22.361.69894-438c598 was discovered to contain a stored… CVSS 3.1MEDIUM 5.4
- TI-2026-23701 OpenWrt Project has a Stack-based Buffer Overflow vulnerability via IPv6 reverse DNS lookup CVSS 4.0CRITICAL 9.5
- TI-2026-23700 OpenWrt Project has Stack-based Buffer Overflow in DNS PTR Query CVSS 4.0CRITICAL 9.5
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences