CVE-2023-5517
Querying RFC 1918 reverse zones may cause an assertion failure when "nxdomain-redirect" is enabled
- Published
- Updated
- Reserved
- Assigned by
- isc
Description
A flaw in query-handling code can cause `named` to exit prematurely with an assertion failure when: - `nxdomain-redirect <domain>;` is configured, and - the resolver receives a PTR query for an RFC 1918 address that would normally result in an authoritative NXDOMAIN response. This issue affects BIND 9 versions 9.12.0 through 9.16.45, 9.18.0 through 9.18.21, 9.19.0 through 9.19.19, 9.16.8-S1 through 9.16.45-S1, and 9.18.11-S1 through 9.18.21-S1.
Timeline
ID reserved
By isc
- 4 months later
· 4 months later
Published
- 12 months later
· 12 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| iscCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 1.3% · top 30% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Weakness
Affected products
What to do
Solution: Upgrade to the patched release most closely related to your current version of BIND 9: 9.16.48, 9.18.24, 9.19.21, 9.16.48-S1, or 9.18.24-S1.
Workaround: Disabling the `nxdomain-redirect` feature makes the faulty code path impossible to reach, preventing this flaw from being exploitable.
Exploitation: We are not aware of any active exploits.
References (7)
- CVE-2023-5517 (opens in a new tab)vendor-advisoryx_transferred
- http://www.openwall.com/lists/oss-security/2024/02/13/1 (opens in a new tab)x_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/PNNHZSZPG2E7NBMBNYPGHCFI4V4XRWNQ/ (opens in a new tab)x_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/RGS7JN6FZXUSTC2XKQHH27574XOULYYJ/ (opens in a new tab)x_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/HVRDSJVZKMCXKKPP6PNR62T7RWZ3YSDZ/ (opens in a new tab)x_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/ZDZFMEKQTZ4L7RY46FCENWFB5MDT263R/ (opens in a new tab)x_transferred
- https://security.netapp.com/advisory/ntap-20240503-0006/ (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2023-5517)Record last updated .