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.

Multiple format string vulnerabilities in lib/silcclient/cliententry.c in Secure Internet Live Conferencing (SILC) Toolkit before 1.1.10, and SILC Client before 1.1.8, allow remote attackers to execute arbitrary code via format string specifiers in a nickname field, related to the (1) silcclientaddclient, (2) silcclientupdateclient, and (3) silcclientnicknameformat functions.

Multiple format string vulnerabilities in lib/silcclient/command.c in Secure Internet Live Conferencing (SILC) Toolkit before 1.1.10, and SILC Client 1.1.8 and earlier, allow remote attackers to execute arbitrary code via format string specifiers in a channel name, related to (1) silcclientcommandtopic, (2) silcclientcommandkick, (3) silcclientcommandleave, and (4) silcclientcommandusers.