SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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.

MEDIUM 5.9EPSS 93.4%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 93.4%, higher than 100% of all known CVEs. Patch or mitigate before the next change window.

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.

CVSS 3.1
5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
93.42% probability · 100th percentile
CISA KEV
Not listed
Weakness
CWE-617
Affected
isc/bind · debian/debian linux · fedoraproject/fedora · opensuse/leap · canonical/ubuntu linux
Source
security-officer@isc.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.