USN-8951-1: c-ares vulnerabilities
It was discovered that c-ares incorrectly parsed certain SOA replies. A
remote attacker could possibly use this issue to cause c-ares to crash,
resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS
and Ubuntu 18.04 LTS. (CVE-2020-22217)
It was discovered that c-ares incorrectly handled certain sortlist strings.
A remote attacker could possibly use this issue to cause c-ares to crash,
resulting in a denial of service, or execute arbitrary code. This issue
only affected Ubuntu 16.04 LTS. (CVE-2022-4904)
It was discovered that c-ares did not properly limit DNS compression
pointer hops or assembled name lengths when parsing DNS names. A remote
attacker could possibly use this issue to cause c-ares to use excessive
resources, resulting in a denial of service. (CVE-2026-69184)
It was discovered that c-ares did not properly validate record count fields
before allocating memory when parsing DNS responses. A remote attacker
could possibly use this issue to cause c-ares to use excessive resources,
resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS
and Ubuntu 26.04 LTS. (CVE-2026-69186)