Fixed
Created: Jan 19, 2021
Updated: Mar 22, 2021
Resolved Date: Mar 21, 2021
Found In Version: 10.18.44.1
Severity: Standard
Applicable for: Wind River Linux LTS 18
Component/s: Userspace
A buffer overflow vulnerability was discovered in the way dnsmasq extract names from DNS packets before validating them with DNSSEC data. An attacker, who can create valid DNS replies, could use this flaw to cause an overflow with arbitrary data in a heap-allocated memory, possibly executing code on the machine. The flaw is in rfc1035.c:extract_name() function, which writes data to the memory pointed by `name` assuming MAXDNAME*2 bytes are available in the buffer. However, in some code execution paths it is possible extract_name() gets passed an offset from the base buffer, thus reducing in practice the number of available bytes that can be written in the buffer.
Upstream patch:
http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=4e96a4be685c9e4445f6ee79ad0b36b9119b502a
CREATE(Triage):(User=admin) [CVE-2020-25682|https://nvd.nist.gov/vuln/detail/CVE-2020-25682]
