Zeroconf: Unbounded DNS record cache allows LAN-local memory exhaustion via multicast flood
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.5epss 0.2%
exploitation probability
0.2%top 85% of all CVEs
observed exploitation
nono source reports it
Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.7, DNSCache._async_add inserted every response record into cache, _expirations, _expire_heap, and service_cache without a cap, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to multicast valid mDNS responses with unique names and cause memory exhaustion, slower cache lookups, slower async_expire passes, and broken discovery, registration, and ServiceBrowser callbacks. This issue is fixed in version 0.149.7.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
python-zeroconf · python-zeroconfReferences
https://github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d322283d148efb2cef6e4https://github.com/python-zeroconf/python-zeroconf/issues/1715https://github.com/python-zeroconf/python-zeroconf/pull/1718https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.7https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-rfg2-pjw2-56x2