An exploitable denial-of-service vulnerability exists in the resource allocation handling of Videolabs libmicrodns 0.1.0. When encountering errors while parsing mDNS messages, some allocated data is not freed, possibly leading to a denial-of-service condition via resource exhaustion. An attacker can send one mDNS message repeatedly to trigger this vulnerability through the function rr_read_RR [5] reads the current resource record, except for the RDATA section. This is read by the loop at in rr_read. For each RR type, a different function is called. When the RR type is 0x10, the function rr_read_TXT is called at [6].

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-6080
• https://security.gentoo.org/glsa/202005-10
• https://talosintelligence.com/vulnerability_reports/TALOS-2020-1002
• https://www.debian.org/security/2020/dsa-4671