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.

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.

Published: 2019-01-16 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-5737 is rated Moderate Risk (54.9/100): CVSS Medium severity, with high exploitation likelihood (EPSS 10.36%, 95th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-5737

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-23 12.32% 10.36% -1.96%
2 2026-06-15 1.23% 12.32% +11.09%
3 2025-11-21 — 1.23% —

Full EPSS history (21 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-5737

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 3.6 [email protected]
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2018-5737

OS Trackers for CVE-2018-5737

vendor priority summary link
alpine high CVE-2018-5737: 1 source package rows (bind); 10 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 0. https://security.alpinelinux.org/vuln/CVE-2018-5737
debian unimportant CVE-2018-5737 unimportant priority: Debian including 1 source packages (bind9), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-5737
redhat medium — https://access.redhat.com/security/cve/CVE-2018-5737
ubuntu medium CVE-2018-5737 medium priority: Ubuntu including 1 source packages (bind9), 5 status rows across 5 suites (artful, bionic, trusty, upstream, xenial): not-affected 4, needs-triage 1. https://ubuntu.com/security/CVE-2018-5737

Affected software / configurations for CVE-2018-5737

Vendor Product Version Raw CPE
isc bind 9.12.0 cpe:2.3:a:isc:bind:9.12.0:*:*:*:*:*:*:*
isc bind 9.12.1 cpe:2.3:a:isc:bind:9.12.1:*:*:*:*:*:*:*
netapp cloud_backup — cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*
netapp data_ontap_edge — cpe:2.3:a:netapp:data_ontap_edge:-:*:*:*:*:*:*:*

References for CVE-2018-5737

URL Tags
http://www.securityfocus.com/bid/104236 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1040942 Third Party Advisory VDB Entry
https://kb.isc.org/docs/aa-01606 Vendor Advisory
https://security.netapp.com/advisory/ntap-20180926-0004/ Third Party Advisory
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