CVE-2018-5737
BIND 9.12's serve-stale implementation can cause an assertion failure in rbtdb.c or other undesirable behavior, even if serve-stale is not enabled.
- Published
- Updated
- Reserved
- Assigned by
- isc
Description
A problem with the implementation of the new serve-stale feature in BIND 9.12 can lead to an assertion failure in rbtdb.c, even when stale-answer-enable is off. Additionally, problematic interaction between the serve-stale feature and NSEC aggressive negative caching can in some cases cause undesirable behavior from named, such as a recursion loop or excessive logging. Deliberate exploitation of this condition could cause operational problems depending on the particular manifestation -- either degradation or denial of service. Affects BIND 9.12.0 and 9.12.1.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| iscCNA (assigner) | 3.0 | Medium5.9 | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.0 | High7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 10.6% · top 4.2% of all CVEs (4 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.9.
Weakness
- Servers running a vulnerable version of BIND (9.12.0, 9.12.1) which permit recursion to clients and which have the max-stale-ttl parameter set to a non-zero value are at risk.
- CWE-617 (opens in a new tab)All about CWE-617 and its CVEs
Affected products
What to do
Solution: The error which can be exploited in this vulnerability is present in only two public release versions of BIND, 9.12.0 and 9.12.1. If you are running an affected version then upgrade to BIND 9.12.1-P2
Workaround: Setting "max-stale-ttl 0;" in named.conf will prevent exploitation of this vulnerability (but will effectively disable the serve-stale feature.) Setting "stale-answer enable off;" is not sufficient to prevent exploitation, max-stale-ttl needs to be set to zero.
References (4)
- 104236 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- https://kb.isc.org/docs/aa-01606 (opens in a new tab)x_refsource_CONFIRMx_transferred
- 1040942 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
- https://security.netapp.com/advisory/ntap-20180926-0004/ (opens in a new tab)x_refsource_CONFIRMx_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-2018-5737)Record last updated .