Time-of-check time-of-use race condition in FRRouting
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In FRRouting FRR before 8.5, the service user (usually frr) can escalate its privileges to root by monitoring the configuration directory (/etc/frr) and replacing config files upon creation with, for example, symlinks to change the ownership of arbitrary files. This is a TOCTOU Race Condition caused by a combination of touch and chown.
Why it matters now
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
Remediation
- Fix · CNA FRRouting (FRRouting) Fixed in 4.5
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 3 products
- Fast Datapath for RHEL 10
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2022-42917
- 2026-10-03 Alias added: GHSA-x36x-qpcf-qwfj
References
More FRRouting vulnerabilities
- TI-2023-20107 FRRouting FRR 7.5.1 through 9.0 and Pica8 PICOS 4.3.3.2 allow a remote attacker to cause… CVSS 3.1HIGH 7.5
- TI-2023-21958 An issue was discovered in FRRouting FRR 9.0. CVSS 3.1CRITICAL 9.8
- TI-2024-29658 An issue was discovered in FRRouting (FRR) through 10.1. CVSS 3.1CRITICAL 9.8
- TI-2023-21957 An issue was discovered in FRRouting FRR through 9.0. CVSS 3.1CRITICAL 9.1
- TI-2023-19790 bgpd/bgp_flowspec.c in FRRouting (FRR) before 8.4.3 mishandles an nlri length of zero, aka a "flowspec overflow." CVSS 3.1CRITICAL 9.8
- TI-2022-17234 An out-of-bounds read in the BGP daemon of FRRouting FRR before 8.4 may lead to a… CVSS 3.1CRITICAL 9.1
Sources
- CVE-2022-42917 · CVE Program
- CVE-2022-42917 · NVD
- FIRST EPSS
- GHSA-x36x-qpcf-qwfj · GitHub Advisory Database · CC BY 4.0
- CVE-2022-42917 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences