CVE-2020-8617 A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c

2020-05-1900:00:00

isc

www.cve.org

7.5 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

8 High

AI Score

Confidence

High

0.973 High

EPSS

Percentile

99.9%

JSON

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.

CNA Affected

[
  {
    "product": "BIND9",
    "vendor": "ISC",
    "versions": [
      {
        "status": "affected",
        "version": "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"
      }
    ]
  }
]