All Samba versions 4.x.x before 4.9.17, 4.10.x before 4.10.11 and 4.11.x
before 4.11.3 have an issue, where the (poorly named) dnsserver RPC pipe
provides administrative facilities to modify DNS records and zones. Samba,
when acting as an AD DC, stores DNS records in LDAP. In AD, the default
permissions on the DNS partition allow creation of new records by
authenticated users. This is used for example to allow machines to
self-register in DNS. If a DNS record was created that case-insensitively
matched the name of the zone, the ldb_qsort() and dns_name_compare()
routines could be confused into reading memory prior to the list of DNS
entries when responding to DnssrvEnumRecords() or DnssrvEnumRecords2() and
so following invalid memory as a pointer.
Source: samba (LP Ubuntu Debian)
Upstream:released (4.11.3,4.10.11,4.9.17)
Ubuntu 12.04 ESM (Precise Pangolin):not-affected
Ubuntu 14.04 ESM (Trusty Tahr):released (2:4.3.11+dfsg-0ubuntu0.14.04.20+esm4)
Ubuntu 16.04 LTS (Xenial Xerus):released (2:4.3.11+dfsg-0ubuntu0.16.04.24)
Ubuntu 18.04 LTS (Bionic Beaver):released (2:4.7.6+dfsg~ubuntu-0ubuntu2.14)
Ubuntu 20.04 LTS (Focal Fossa):released (2:4.11.5+dfsg-1ubuntu1)
More Information

Updated: 2020-07-28 20:06:44 UTC (commit d26b6ca9f5b3adb89bb036ce73ae7dab894935ec)