A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. A remote attacker who can create valid DNS replies could use this flaw to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name() which could be abused to make the code execute memcpy() with a negative size in get_rdata() and cause a crash in dnsmasq resulting in a denial of service. The highest threat from this vulnerability is to system availability.

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dnsmasq: heap-based buffer overflow with large memcpy in get_rdata() when DNSSEC is enabled

A flaw was found in dnsmasq. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. A remote attacker, who can create valid DNS replies, could use this flaw to cause an overflow in a heap-allocated memory. This flaw is cause...

dnsmasq: heap-based buffer overflow with large memcpy in get_rdata() when DNSSEC is enabled

A flaw was found in dnsmasq. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. A remote attacker, who can create valid DNS replies, could use this flaw to cause an overflow in a heap-allocated memory. This flaw is cause...

PT-2021-3538

Name of the Vulnerable Software and Affected Versions dnsmasq versions prior to 2.83 Description A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled. This issue is caused by the lack of length checks in the extract name function, which could be abused to make the code...