CVE-2018-5745

An assertion failure can occur if a trust anchor rolls over to an unsupported key algorithm when using managed-keys

4.9MediumCVSS base score
2.3%Exploitation in 30 daysEPSS · top 17% of all CVEs
NoKnown exploitednot in CISA's KEV catalog
NonePublic exploitsnone known yet

Published: 9 Oct 2019
Updated: 16 Sept 2024
Reserved: 17 Jan 2018
Assigned by: isc
NVD status: Modified

Weakness

This particular vulnerability would be very difficult for an arbitrary attacker to use because it requires an operator to have BIND configured to use a trust anchor managed by the attacker. However, if successfully exercised, the defect will cause named to deliberately exit after encountering an assertion failure. It is more likely, perhaps, that this bug could be encountered accidentally, as not all versions of BIND support the same set of cryptographic algorithms. Specifically, recent branches of BIND have begun deliberately removing support for cryptographic algorithms that are now deprecated (for example because they are no longer considered sufficiently secure.) This vulnerability could be encountered if a resolver running a version of BIND which has removed support for deprecated algorithms is configured to use a trust anchor which elects to change algorithm types to one of those deprecated algorithms. Support for GOST was removed from BIND in 9.13.1. Support for DSA was removed from BIND in 9.13.4 Support for RSAMD5 will be removed from future BIND releases in the 9.13 branch and higher.
CWE-327

Description

"managed-keys" is a feature which allows a BIND resolver to automatically maintain the keys used by trust anchors which operators configure for use in DNSSEC validation. Due to an error in the managed-keys feature it is possible for a BIND server which uses managed-keys to exit due to an assertion failure if, during key rollover, a trust anchor's keys are replaced with keys which use an unsupported algorithm. Versions affected: BIND 9.9.0 -> 9.10.8-P1, 9.11.0 -> 9.11.5-P1, 9.12.0 -> 9.12.3-P1, and versions 9.9.3-S1 -> 9.11.5-S3 of BIND 9 Supported Preview Edition. Versions 9.13.0 -> 9.13.6 of the 9.13 development branch are also affected. Versions prior to BIND 9.9.0 have not been evaluated for vulnerability to CVE-2018-5745.

Timeline

2018
17 Jan 2018
17 Jan 2018
ID reserved
By isc
2019
9 Oct 201921 months later
9 Oct 2019· 21 months later
Published
2024
16 Sept 20245 years later
16 Sept 2024· 5 years 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

CVSS scores of CVE-2018-5745, by who scored it
Scored by	CVSS	Score	Vector
iscCNA (assigner)	3.0	Medium4.9	CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
NVDNVD · Modified	3.1	Medium4.9	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

EPSS (exploitation in 30 days): 2.3% · top 17% of all CVEs (9 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.9.

Affected products

ISC · BIND 9
- affected BIND 9.9.0 -> 9.10.8-P1, 9.11.0 -> 9.11.5-P1, 9.12.0 -> 9.12.3-P1, and versions 9.9.3-S1 -> 9.11.5-S3 of BIND 9 Supported Preview Edition. Versions 9.13.0 -> 9.13.6 of the 9.13 development branch are also affected. Versions prior to BIND 9.9.0 have not been evaluated for vulnerability to CVE-2018-5745.

What to do

Solution: Upgrade to a version of BIND containing a fix preventing the assertion failure. >= BIND 9.11.5-P4 >= BIND 9.12.3-P4 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. >= BIND 9.11.5-S5

References

https://kb.isc.org/docs/cve-2018-5745 (opens in a new tab)x_refsource_CONFIRMx_transferred
RHSA-2019:3552 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

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Record last updated 16 Sept 2024, 23:51 UTC.