Zeroconf: Unvalidated rdlength in record payload readers allows LAN-local cache corruption via crafted mDNS packet
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.3epss 0.2%
exploitation probability
0.2%top 90% of all CVEs
observed exploitation
nono source reports it
Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.16, _read_character_string and _read_string in src/zeroconf/_protocol/incoming.py advanced self.offset by attacker-declared RDLENGTH without checking it against self._data_len, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to send a TXT, HINFO, or A/AAAA record with rdlength=65535 and seed DNSCache and ServiceInfo.properties with truncated, attacker-shaped key/value or address records. This issue is fixed in version 0.149.16.
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Affected products
python-zeroconf · python-zeroconfReferences
https://github.com/python-zeroconf/python-zeroconf/commit/544449596e645fcaad3834fa0cb614a54f847a82https://github.com/python-zeroconf/python-zeroconf/issues/1752https://github.com/python-zeroconf/python-zeroconf/pull/1756https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.16https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-qc2x-6f54-m6h9