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.
[
{
"product": "dnsmasq",
"vendor": "n/a",
"versions": [
{
"status": "affected",
"version": "dnsmasq 2.83"
}
]
}
]
bugzilla.redhat.com/show_bug.cgi?id=1882018
lists.debian.org/debian-lts-announce/2021/03/msg00027.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
security.gentoo.org/glsa/202101-17
www.debian.org/security/2021/dsa-4844
www.jsof-tech.com/disclosures/dnspooq/