Buffer overflow in InspIRCd before 1.1.18, when using the namesx and uhnames modules, allows remote attackers to cause a denial of service (daemon crash) via a large number of channel users with crafted nicknames, idents, and long hostnames.

Heap-based buffer overflow in dns.cpp in InspIRCd 2.0.5 might allow remote attackers to execute arbitrary code via a crafted DNS query that uses compression.

inspircd in Debian before 2.0.7 does not properly handle unsigned integers. NOTE: This vulnerability exists because of an incomplete fix to CVE-2012-1836.

Buffer underflow vulnerability in the Debian inspircd package before 2.0.5-1+deb7u1 for wheezy and before 2.0.16-1 for jessie and sid. NOTE: This issue exists as an additional issue from an incomplete fix of CVE-2012-1836.

The DNS::GetResult function in dns.cpp in InspIRCd before 2.0.19 allows remote DNS servers to cause a denial of service (netsplit) via an invalid character in a PTR response, as demonstrated by a "\032" (whitespace) character in a hostname.

The m_sasl module in InspIRCd before 2.0.23, when used with a service that supports SASL_EXTERNAL authentication, allows remote attackers to spoof certificate fingerprints and consequently log in as another user via a crafted SASL message.