Debian Security Advisory

DLA-2568-1 bind9 -- LTS security update

Date Reported:

19 Feb 2021

Affected Packages:

bind9

Vulnerable:

Yes

Security database references:

In Mitre's CVE dictionary: CVE-2020-8625.

More information:

It was discovered that there was a buffer overflow attack in the bind9 DNS server caused by an issue in the GSSAPI ("Generic Security Services") security policy negotiation.

CVE-2020-8625
BIND servers are vulnerable if they are running an affected version and are configured to use GSS-TSIG features. In a configuration which uses BIND's default settings the vulnerable code path is not exposed, but a server can be rendered vulnerable by explicitly setting valid values for the tkey-gssapi-keytab or tkey-gssapi-credentialconfiguration options. Although the default configuration is not vulnerable, GSS-TSIG is frequently used in networks where BIND is integrated with Samba, as well as in mixed-server environments that combine BIND servers with Active Directory domain controllers. The most likely outcome of a successful exploitation of the vulnerability is a crash of the named process. However, remote code execution, while unproven, is theoretically possible. Affects: BIND 9.5.0 -> 9.11.27, 9.12.0 -> 9.16.11, and versions BIND 9.11.3-S1 -> 9.11.27-S1 and 9.16.8-S1 -> 9.16.11-S1 of BIND Supported Preview Edition. Also release versions 9.17.0 -> 9.17.1 of the BIND 9.17 development branch

For Debian 9 Stretch, these problems have been fixed in version 1:9.10.3.dfsg.P4-12.3+deb9u8.

We recommend that you upgrade your bind9 packages.

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: https://wiki.debian.org/LTS