The SILCSERVERCMDFUNC function in apps/silcd/command.c in silc-server 1.0.2 allows remote attackers to cause a denial of service (NULL dereference and daemon crash) via a request without a cipher algorithm and an invalid HMAC algorithm.

Secure Internet Live Conferencing (SILC) Server before 1.1.1 allows remote attackers to cause a denial of service (daemon crash) via a NEWCLIENT packet without a nickname.

The silcpkcs1decode function in the silccrypt library (silcpkcs1.c) in Secure Internet Live Conferencing (SILC) Toolkit before 1.1.7, SILC Client before 1.1.4, and SILC Server before 1.1.2 allows remote attackers to execute arbitrary code via a crafted PKCS#1 message, which triggers an integer underflow, signedness error, and a buffer overflow. NOTE: the researcher describes this as an integer overflow, but CVE uses the "underflow" term in cases of wraparound from unsigned subtraction.