Packages
- c-ares - library for asynchronous name resolution
Details
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...
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)
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 | ||
|---|---|---|---|
| 26.04 LTS resolute | libcares2 – 1.34.6-1ubuntu0.2 | ||
| 24.04 LTS noble | libcares2 – 1.27.0-1.0ubuntu1.1 | ||
| 22.04 LTS jammy | libc-ares2 – 1.18.1-1ubuntu0.22.04.4 | ||
| 20.04 LTS focal | libc-ares2 – 1.15.0-1ubuntu0.5+esm1 | ||
| 18.04 LTS bionic | libc-ares2 – 1.14.0-1ubuntu0.2+esm3 | ||
| 16.04 LTS xenial | libc-ares2 – 1.10.0-3ubuntu0.2+esm4 | ||
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