A Reachable Assertion issue was discovered in the KDC in MIT Kerberos 5 (aka krb5) before 1.17. If an attacker can obtain a krbtgt ticket using an older encryption type (single-DES, triple-DES, or RC4), the attacker can crash the KDC by making an S4U2Self request.
{ "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro", "ubuntu_priority": "medium", "binaries": [ { "libk5crypto3": "1.12+dfsg-2ubuntu5.4+esm1", "libkdb5-7": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-otp-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-pkinit-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-kdc": "1.12+dfsg-2ubuntu5.4+esm1", "libkrb5-dbg": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-admin-server": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-user-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-otp": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-user": "1.12+dfsg-2ubuntu5.4+esm1", "libkrb5-3-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "libgssrpc4": "1.12+dfsg-2ubuntu5.4+esm1", "libgssapi-krb5-2-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "libkrad0": "1.12+dfsg-2ubuntu5.4+esm1", "libkrb5-3": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-gss-samples-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "libkrad-dev": "1.12+dfsg-2ubuntu5.4+esm1", "libkrb5support0-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "libkdb5-7-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-multidev": "1.12+dfsg-2ubuntu5.4+esm1", "libkadm5srv-mit9": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-gss-samples": "1.12+dfsg-2ubuntu5.4+esm1", "libkadm5srv-mit9-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "libkrad0-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-kdc-ldap-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "libk5crypto3-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "libkadm5clnt-mit9": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-kdc-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-locales": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-doc": "1.12+dfsg-2ubuntu5.4+esm1", "libkadm5clnt-mit9-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-pkinit": "1.12+dfsg-2ubuntu5.4+esm1", "libkrb5-dev": "1.12+dfsg-2ubuntu5.4+esm1", "libkrb5support0": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-admin-server-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "libgssapi-krb5-2": "1.12+dfsg-2ubuntu5.4+esm1", "krb5-kdc-ldap": "1.12+dfsg-2ubuntu5.4+esm1", "libgssrpc4-dbgsym": "1.12+dfsg-2ubuntu5.4+esm1", "libkadm5srv-mit8": "1.12+dfsg-2ubuntu5.4+esm1" } ] }
{ "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro", "ubuntu_priority": "medium", "binaries": [ { "libk5crypto3": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-otp-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-pkinit-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkrb5-dev-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-kdc": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkrb5-dbg": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-admin-server": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-user-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-otp": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkdb5-8": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkrb5-3-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-user": "1.13.2+dfsg-5ubuntu2.2+esm3", "libgssrpc4": "1.13.2+dfsg-5ubuntu2.2+esm3", "libgssapi-krb5-2-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkdb5-8-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkrad0": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkrb5-3": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-gss-samples-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkrad-dev": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkrb5support0-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-multidev": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkadm5srv-mit9": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-gss-samples": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkadm5srv-mit9-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkrad0-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-kdc-ldap-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-multidev-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "libk5crypto3-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkadm5clnt-mit9": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-k5tls-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-locales": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkrad-dev-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-doc": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkadm5clnt-mit9-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-pkinit": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkrb5-dev": "1.13.2+dfsg-5ubuntu2.2+esm3", "libkrb5support0": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-admin-server-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "libgssapi-krb5-2": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-k5tls": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-kdc-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3", "krb5-kdc-ldap": "1.13.2+dfsg-5ubuntu2.2+esm3", "libgssrpc4-dbgsym": "1.13.2+dfsg-5ubuntu2.2+esm3" } ] }
{ "availability": "No subscription required", "ubuntu_priority": "medium", "binaries": [ { "libk5crypto3": "1.16-2ubuntu0.3", "krb5-otp-dbgsym": "1.16-2ubuntu0.3", "krb5-kpropd": "1.16-2ubuntu0.3", "libkadm5srv-mit11": "1.16-2ubuntu0.3", "krb5-pkinit-dbgsym": "1.16-2ubuntu0.3", "krb5-kdc": "1.16-2ubuntu0.3", "libkrb5-dbg": "1.16-2ubuntu0.3", "krb5-admin-server": "1.16-2ubuntu0.3", "krb5-user-dbgsym": "1.16-2ubuntu0.3", "krb5-otp": "1.16-2ubuntu0.3", "krb5-user": "1.16-2ubuntu0.3", "libgssrpc4": "1.16-2ubuntu0.3", "libkrad0": "1.16-2ubuntu0.3", "libkrb5-3": "1.16-2ubuntu0.3", "krb5-gss-samples-dbgsym": "1.16-2ubuntu0.3", "libkrad-dev": "1.16-2ubuntu0.3", "libkadm5clnt-mit11": "1.16-2ubuntu0.3", "krb5-multidev": "1.16-2ubuntu0.3", "krb5-gss-samples": "1.16-2ubuntu0.3", "krb5-kpropd-dbgsym": "1.16-2ubuntu0.3", "krb5-kdc-ldap-dbgsym": "1.16-2ubuntu0.3", "krb5-k5tls-dbgsym": "1.16-2ubuntu0.3", "krb5-locales": "1.16-2ubuntu0.3", "krb5-kdc-dbgsym": "1.16-2ubuntu0.3", "krb5-doc": "1.16-2ubuntu0.3", "libkrb5support0": "1.16-2ubuntu0.3", "krb5-pkinit": "1.16-2ubuntu0.3", "libkrb5-dev": "1.16-2ubuntu0.3", "krb5-admin-server-dbgsym": "1.16-2ubuntu0.3", "libgssapi-krb5-2": "1.16-2ubuntu0.3", "krb5-k5tls": "1.16-2ubuntu0.3", "krb5-kdc-ldap": "1.16-2ubuntu0.3", "libkdb5-9": "1.16-2ubuntu0.3" } ] }
{ "availability": "No subscription required", "ubuntu_priority": "medium", "binaries": [ { "libk5crypto3": "1.17-6ubuntu4", "krb5-otp-dbgsym": "1.17-6ubuntu4", "krb5-kpropd": "1.17-6ubuntu4", "libkadm5srv-mit11": "1.17-6ubuntu4", "krb5-pkinit-dbgsym": "1.17-6ubuntu4", "krb5-kdc": "1.17-6ubuntu4", "libkrb5-dbg": "1.17-6ubuntu4", "krb5-admin-server": "1.17-6ubuntu4", "krb5-user-dbgsym": "1.17-6ubuntu4", "krb5-otp": "1.17-6ubuntu4", "krb5-user": "1.17-6ubuntu4", "libgssrpc4": "1.17-6ubuntu4", "libkrad0": "1.17-6ubuntu4", "libkrb5-3": "1.17-6ubuntu4", "krb5-gss-samples-dbgsym": "1.17-6ubuntu4", "libkrad-dev": "1.17-6ubuntu4", "libkadm5clnt-mit11": "1.17-6ubuntu4", "krb5-multidev": "1.17-6ubuntu4", "krb5-gss-samples": "1.17-6ubuntu4", "krb5-kpropd-dbgsym": "1.17-6ubuntu4", "krb5-kdc-ldap-dbgsym": "1.17-6ubuntu4", "krb5-k5tls-dbgsym": "1.17-6ubuntu4", "krb5-locales": "1.17-6ubuntu4", "krb5-kdc-dbgsym": "1.17-6ubuntu4", "krb5-doc": "1.17-6ubuntu4", "libkrb5support0": "1.17-6ubuntu4", "krb5-pkinit": "1.17-6ubuntu4", "libkrb5-dev": "1.17-6ubuntu4", "krb5-admin-server-dbgsym": "1.17-6ubuntu4", "libgssapi-krb5-2": "1.17-6ubuntu4", "krb5-k5tls": "1.17-6ubuntu4", "krb5-kdc-ldap": "1.17-6ubuntu4", "libkdb5-9": "1.17-6ubuntu4" } ] }