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MEDIUM

CVE-2020-8617

CVSS v3

5.9

MEDIUM

EPSS Score

93.4 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2020-8617 Red Hat Product Security2,918 products fixed · 2 known affected

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

    bind as a component of Red Hat Enterprise Linux 5 · bind97 as a component of Red Hat Enterprise Linux 5

  • RHSA-2020:3475 Red Hat Product Security151 products fixed

    Red Hat Security Advisory: bind security update

  • RHSA-2020:3470 Red Hat Product Security90 products fixed

    Red Hat Security Advisory: bind security update

  • RHSA-2020:3471 Red Hat Product Security25 products fixed

    Red Hat Security Advisory: bind security update

  • RHSA-2020:3433 Red Hat Product Security90 products fixed

    Red Hat Security Advisory: bind security update

  • RHSA-2020:3378 Red Hat Product Security13 products fixed

    Red Hat Security Advisory: bind security update

7 more advisories

Full record on NVD

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.

Technical details

Published
2020-05-19
Exploit-DB
EDB-48521

Frequently asked questions

What is 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.

Is CVE-2020-8617 actively exploited?

Active exploitation of CVE-2020-8617 has not been confirmed. Its EPSS score was 93.4% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-8617?

CVE-2020-8617 has a CVSS v3 base score of 5.9 (MEDIUM severity).

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