Ubuntu Security Notices
USN-4635-1

USN-4635-1: Kerberos vulnerability

Publication date

17 November 2020

Overview

Kerberos could be made to consume unlimited resources if it received specially crafted ASN.1.

Releases

20.10 20.04 LTS 18.04 LTS 16.04 LTS 14.04 LTS

Packages

krb5 - MIT Kerberos Network Authentication Protocol

Details

Demi Obenour discovered that Kerberos incorrectly handled certain ASN.1.
An attacker could possibly use this issue to cause a denial of service.

Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release	Package Version
20.10 groovy	krb5-admin-server – 1.17-10ubuntu0.1
	krb5-k5tls – 1.17-10ubuntu0.1
	krb5-kdc – 1.17-10ubuntu0.1
	krb5-kdc-ldap – 1.17-10ubuntu0.1
	krb5-kpropd – 1.17-10ubuntu0.1
	krb5-locales – 1.17-10ubuntu0.1
	krb5-multidev – 1.17-10ubuntu0.1
	krb5-otp – 1.17-10ubuntu0.1
	krb5-pkinit – 1.17-10ubuntu0.1
	krb5-user – 1.17-10ubuntu0.1
	libgssapi-krb5-2 – 1.17-10ubuntu0.1
	libgssrpc4 – 1.17-10ubuntu0.1
	libk5crypto3 – 1.17-10ubuntu0.1
	libkadm5clnt-mit11 – 1.17-10ubuntu0.1
	libkadm5srv-mit11 – 1.17-10ubuntu0.1
	libkdb5-9 – 1.17-10ubuntu0.1
	libkrad0 – 1.17-10ubuntu0.1
	libkrb5-3 – 1.17-10ubuntu0.1
	libkrb5support0 – 1.17-10ubuntu0.1
20.04 focal	krb5-admin-server – 1.17-6ubuntu4.1
	krb5-k5tls – 1.17-6ubuntu4.1
	krb5-kdc – 1.17-6ubuntu4.1
	krb5-kdc-ldap – 1.17-6ubuntu4.1
	krb5-kpropd – 1.17-6ubuntu4.1
	krb5-locales – 1.17-6ubuntu4.1
	krb5-multidev – 1.17-6ubuntu4.1
	krb5-otp – 1.17-6ubuntu4.1
	krb5-pkinit – 1.17-6ubuntu4.1
	krb5-user – 1.17-6ubuntu4.1
	libgssapi-krb5-2 – 1.17-6ubuntu4.1
	libgssrpc4 – 1.17-6ubuntu4.1
	libk5crypto3 – 1.17-6ubuntu4.1
	libkadm5clnt-mit11 – 1.17-6ubuntu4.1
	libkadm5srv-mit11 – 1.17-6ubuntu4.1
	libkdb5-9 – 1.17-6ubuntu4.1
	libkrad0 – 1.17-6ubuntu4.1
	libkrb5-3 – 1.17-6ubuntu4.1
	libkrb5support0 – 1.17-6ubuntu4.1
18.04 bionic	krb5-admin-server – 1.16-2ubuntu0.2
	krb5-k5tls – 1.16-2ubuntu0.2
	krb5-kdc – 1.16-2ubuntu0.2
	krb5-kdc-ldap – 1.16-2ubuntu0.2
	krb5-kpropd – 1.16-2ubuntu0.2
	krb5-locales – 1.16-2ubuntu0.2
	krb5-otp – 1.16-2ubuntu0.2
	krb5-pkinit – 1.16-2ubuntu0.2
	krb5-user – 1.16-2ubuntu0.2
	libgssapi-krb5-2 – 1.16-2ubuntu0.2
	libgssrpc4 – 1.16-2ubuntu0.2
	libk5crypto3 – 1.16-2ubuntu0.2
	libkadm5clnt-mit11 – 1.16-2ubuntu0.2
	libkadm5srv-mit11 – 1.16-2ubuntu0.2
	libkdb5-9 – 1.16-2ubuntu0.2
	libkrad0 – 1.16-2ubuntu0.2
	libkrb5-3 – 1.16-2ubuntu0.2
	libkrb5support0 – 1.16-2ubuntu0.2
16.04 xenial	krb5-admin-server – 1.13.2+dfsg-5ubuntu2.2
	krb5-k5tls – 1.13.2+dfsg-5ubuntu2.2
	krb5-kdc – 1.13.2+dfsg-5ubuntu2.2
	krb5-kdc-ldap – 1.13.2+dfsg-5ubuntu2.2
	krb5-locales – 1.13.2+dfsg-5ubuntu2.2
	krb5-multidev – 1.13.2+dfsg-5ubuntu2.2
	krb5-otp – 1.13.2+dfsg-5ubuntu2.2
	krb5-pkinit – 1.13.2+dfsg-5ubuntu2.2
	krb5-user – 1.13.2+dfsg-5ubuntu2.2
	libgssapi-krb5-2 – 1.13.2+dfsg-5ubuntu2.2
	libgssrpc4 – 1.13.2+dfsg-5ubuntu2.2
	libk5crypto3 – 1.13.2+dfsg-5ubuntu2.2
	libkadm5clnt-mit9 – 1.13.2+dfsg-5ubuntu2.2
	libkadm5srv-mit9 – 1.13.2+dfsg-5ubuntu2.2
	libkdb5-8 – 1.13.2+dfsg-5ubuntu2.2
	libkrad0 – 1.13.2+dfsg-5ubuntu2.2
	libkrb5-3 – 1.13.2+dfsg-5ubuntu2.2
	libkrb5support0 – 1.13.2+dfsg-5ubuntu2.2
14.04 trusty	krb5-admin-server – 1.12+dfsg-2ubuntu5.4+esm2
	krb5-kdc – 1.12+dfsg-2ubuntu5.4+esm2
	krb5-kdc-ldap – 1.12+dfsg-2ubuntu5.4+esm2
	krb5-locales – 1.12+dfsg-2ubuntu5.4+esm2
	krb5-multidev – 1.12+dfsg-2ubuntu5.4+esm2
	krb5-otp – 1.12+dfsg-2ubuntu5.4+esm2
	krb5-pkinit – 1.12+dfsg-2ubuntu5.4+esm2
	krb5-user – 1.12+dfsg-2ubuntu5.4+esm2
	libgssapi-krb5-2 – 1.12+dfsg-2ubuntu5.4+esm2
	libgssrpc4 – 1.12+dfsg-2ubuntu5.4+esm2
	libk5crypto3 – 1.12+dfsg-2ubuntu5.4+esm2
	libkadm5clnt-mit9 – 1.12+dfsg-2ubuntu5.4+esm2
	libkadm5srv-mit8 – 1.12+dfsg-2ubuntu5.4+esm2
	libkadm5srv-mit9 – 1.12+dfsg-2ubuntu5.4+esm2
	libkdb5-7 – 1.12+dfsg-2ubuntu5.4+esm2
	libkrad0 – 1.12+dfsg-2ubuntu5.4+esm2
	libkrb5-3 – 1.12+dfsg-2ubuntu5.4+esm2
	libkrb5support0 – 1.12+dfsg-2ubuntu5.4+esm2

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References

CVE-2020-28196

CVE-2020-28196