Resource exhaustion in Isc Bind
CVE-2019-6477
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 releasing these multiple resources can cause it to become unresponsive, even for queries that can be answered authoritatively or from cache. (This is most likely to be perceived as an intermittent server problem).
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.041 (90.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 91st percentile — 90.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.041 · newest: 0.041 · change: 0.000
Affected products
- Isc Bind — versions 9.11.5, 9.11.6, 9.11.12
- Isc Bind9 — versions 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
- Fedoraproject Fedora — versions 30, 31
Weakness classification (CWE)
Public proof-of-concept exploits
References
- kb.isc.org/docs/cve-2019-6477 (Third Party Advisory)
- www.synology.com/security/advisory/Synology_SA_19_39 (Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- support.f5.com/csp/article/K15840535
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- www.debian.org/security/2020/dsa-4689 (vendor-advisory)
- lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.html (vendor-advisory)
- lists.opensuse.org/opensuse-security-announce/2020-10/msg00044.html (vendor-advisory)
Frequently asked questions
- What is CVE-2019-6477?
- CVE-2019-6477 is a high-severity vulnerability in Isc Bind, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2019-11-26.
- How severe is CVE-2019-6477?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2019-6477 known to be exploited?
- 8 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.