CVE-2020-8617
A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c
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.
- Affected
- ISC · BIND9
- CVSS v3.1 NVD
- 5.9 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS v3.1 ISC
- 7.5 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS v2.0 NVD
- 4.3 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P - EPSS
- 93.42% chance of exploitation in the next 30 days, 100th percentile
- Published
- 2020-05-19
- Updated
- 2024-09-16
Proof-of-concept exploits (2)
- gothburz/cve-2020-86170★ · 2020-05-22
- knqyf263/CVE-2020-861745★ · 2020-05-20
Metasploit modules (1)
ExploitDB entries (1)
Security advisories
- https://kb.isc.org/docs/cve-2020-8617
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.html
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00044.html
- http://packetstormsecurity.com/files/157836/BIND-TSIG-Denial-Of-Service.html
- http://www.openwall.com/lists/oss-security/2020/05/19/4
- https://lists.debian.org/debian-lts-announce/2020/05/msg00031.html
- https://security.netapp.com/advisory/ntap-20200522-0002
- https://usn.ubuntu.com/4365-1
- https://usn.ubuntu.com/4365-2
- https://www.debian.org/security/2020/dsa-4689