Use of uninitialized resource in FreeBSD
Priority LOW 26CWE-908Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-908 and the CVSS impact.
Summary
In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, and 11.3-RELEASE before 11.3-RELEASE-p7, a TCP SYN-ACK or challenge TCP-ACK segment over IPv6 that is transmitted or retransmitted does not properly initialize the Traffic Class field disclosing one byte of kernel memory over the network.
Why it matters now
EPSS 0.01169 67th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | FreeBSD | 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, 11.3-RELEASE before 11.3-RELEASE-p7 | — | No fix listed | CNA |
- FreeBSD Vendor— Affected 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, 11.3-RELEASE before 11.3-RELEASE-p7 Fixed in — No fix listed CNA
CPE configurations NVD · 10
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:freebsd:freebsd:11.3:-:*:*:*:*:*:* | 11.3 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:11.3:p1:*:*:*:*:*:* | 11.3 p1 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:11.3:p2:*:*:*:*:*:* | 11.3 p2 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:11.3:p3:*:*:*:*:*:* | 11.3 p3 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:11.3:p4:*:*:*:*:*:* | 11.3 p4 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:11.3:p5:*:*:*:*:*:* | 11.3 p5 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:11.3:p6:*:*:*:*:*:* | 11.3 p6 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:12.1:-:*:*:*:*:*:* | 12.1 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:12.1:p1:*:*:*:*:*:* | 12.1 p1 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:12.1:p2:*:*:*:*:*:* | 12.1 p2 | Vulnerable | FreeBSD |
- cpe:2.3:o:freebsd:freebsd:11.3:-:*:*:*:*:*:* Versions 11.3 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:11.3:p1:*:*:*:*:*:* Versions 11.3 p1 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:11.3:p2:*:*:*:*:*:* Versions 11.3 p2 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:11.3:p3:*:*:*:*:*:* Versions 11.3 p3 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:11.3:p4:*:*:*:*:*:* Versions 11.3 p4 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:11.3:p5:*:*:*:*:*:* Versions 11.3 p5 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:11.3:p6:*:*:*:*:*:* Versions 11.3 p6 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:12.1:-:*:*:*:*:*:* Versions 12.1 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:12.1:p1:*:*:*:*:*:* Versions 12.1 p1 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:12.1:p2:*:*:*:*:*:* Versions 12.1 p2 Vulnerable ·FreeBSD
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2020-7451
- 2026-10-03 Alias added: GHSA-vv76-2436-qvh9
References
More Freebsd vulnerabilities
- TI-2011-04182 Buffer overflow in libtelnet/encrypt.c in telnetd in FreeBSD 7.3 through 9.0, MIT… CVSS 2.0HIGH 10.0
- TI-2007-03684 Integer overflow in print-bgp.c in the BGP dissector in tcpdump 3.9.6 and earlier allows… CVSS 3.1CRITICAL 9.8
- TI-2002-00376 Integer overflow in xdr_array function in RPC servers for operating systems that use… CVSS 3.1CRITICAL 9.8
- TI-2024-05929 Openssh: regresshion - race condition in ssh allows rce/dos CVSS 3.1HIGH 8.1
- TI-2003-00437 Off-by-one error in the fb_realpath() function, as derived from the realpath function in… CVSS 3.1CRITICAL 9.8
- TI-2003-00642 The prescan function in Sendmail 8.12.9 allows remote attackers to execute arbitrary code… CVSS 2.0HIGH 10.0
Sources
- CVE-2020-7451 · CVE Program
- CVE-2020-7451 · NVD
- FIRST EPSS
- GHSA-vv76-2436-qvh9 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences