CVE-2019-6477 — With pipelining enabled each incoming query on a TCP connection requires a simil

With pipelining enabled each incoming query on a TCP connection requires a similar resource allocation to a query received via UDP or via TCP without pipelining enabled. A client using a TCP-pipelined connection to a server could consume more resources than the server has been pr

01What is this vulnerability?

With pipelining enabled each incoming query on a TCP connection requires a similar resource allocation to a query received via UDP or via TCP without pipelining enabled. A client using a TCP-pipelined connection to a server could consume more resources than the server has been provisioned to handle. When a TCP connection with a large number of pipelined queries is closed, the load on the server…

02Affected products

Vendor	Product	Versions
ISC	BIND9	9.11.6-P1 -> 9.11.12, 9.12.4-P1 -> 9.12.4-P2, 9.14.1 -> 9.14.7, and versions 9.11.5-S6 -> 9.11.12-S1 of BIND 9 Supported Preview Edition. Versions 9.15.0 -> 9.15.5 of the BIND 9.15 development branch are also affected

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-11-26T16:11:16.500Z
• Last modified: 2024-09-16T16:47:45.899Z

09References

• kb.isc.org — https://kb.isc.org/docs/cve-2019-6477
• www.synology.com — https://www.synology.com/security/advisory/Synology_SA_19_39
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
• support.f5.com — https://support.f5.com/csp/article/K15840535?utm_source=f5support&amp%3Butm_medi…
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
• www.debian.org — https://www.debian.org/security/2020/dsa-4689
• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.html
• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00044.html