Vulnerability in Isc Bind
CVE-2020-8617
Using a specially-crafted message, an attacker may potentially cause a BIND server to reach an inconsistent state if the attacker knows (or successfully guesses) the name of a TSIG key used by the server. Since BIND, by default, configures a local session key even on servers whose configuration does not otherwise make use of it, almost all current BIND servers are vulnerable. In releases of BIND dating from March 2018 and after, an assertion check in tsig.c detects this inconsistent state and deliberately exits. Prior to the introduction of the check the server would continue operating in an inconsistent state, with potentially harmful results.
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: 0.934 (99.8th percentile), scored .
High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.934 · newest: 0.934 · change: 0.000
Affected products
- Isc Bind — versions 9.12.4, 9.9.3, 9.10.5
- Isc Bind9 — versions 9.0.0 -> 9.11.18, 9.12.0 -> 9.12.4-P2, 9.14.0 -> 9.14.11, 9.16.0 -> 9.16.2, and releases 9.17.0 -> 9.17.1 of the 9.17 experimental development branch. All releases in the obsolete 9.13 and 9.15 development branches. All releases of BIND Supported Preview Edition from 9.9.3-S1 -> 9.11.18-S1
- Canonical Ubuntu Linux — versions 12.04, 14.04, 16.04
- Debian Linux — versions 8.0, 9.0, 10.0
- Fedoraproject Fedora — versions 31, 32
- openSUSE Leap — versions 15.1, 15.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- kb.isc.org/docs/cve-2020-8617 (Patch, Vendor Advisory)
- www.openwall.com/lists/oss-security/2020/05/19/4 (mailing-list, Patch, Mailing List, Third Party Advisory)
- www.debian.org/security/2020/dsa-4689 (vendor-advisory, Third Party Advisory)
- security.netapp.com/advisory/ntap-20200522-0002/ (Third Party Advisory)
- packetstormsecurity.com/files/157836/BIND-TSIG-Denial-Of-Service.html (VDB Entry, Third Party Advisory)
- usn.ubuntu.com/4365-2/ (vendor-advisory, Third Party Advisory)
- usn.ubuntu.com/4365-1/ (vendor-advisory, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2020/05/msg00031.html (mailing-list, Mailing List, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
Frequently asked questions
- What is CVE-2020-8617?
- CVE-2020-8617 is a high-severity vulnerability in Isc Bind, classified under Reachable Assertion. CVSS score: 7.5/10. Published 2020-05-19.
- How severe is CVE-2020-8617?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2020-8617 known to be exploited?
- 34 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.