CVE-2020-8617

A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c

MEDIUM
5.9
CVSS Score
Published: May 19, 2020 at 02:05 PM UTC
Updated: June 17, 2026 at 03:26 AM UTC
5 products affected across 5 vendorsDebian LinuxFedoraUbuntu Linux

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Severity
MEDIUM5.9
Exploit prediction
EPSS 93%

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≥ 9.9.3-S19.0.0 ≤ v ≤ 9.11.189.12.0 ≤ v ≤ 9.12.49.13.0 ≤ v ≤ 9.13.79.14.0 ≤ v ≤ 9.14.119.15.0 ≤ v ≤ 9.15.69.16.0 ≤ v ≤ 9.16.29.17.0 ≤ v ≤ 9.17.19.10.5 s19.10.7 s19.11.3 s19.11.5 s39.11.5 s59.11.6 s19.11.7 s19.11.8 s19.12.4 p19.12.4 p29.9.3 s1

CVSS

Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-617

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