pidgin: Crash in IRC protocol plug-in by listing set of users (/who command) upon session startup

The irc_msg_who function in msgs.c in the IRC protocol plugin in libpurple 2.8.0 through 2.9.0 in Pidgin before 2.10.0 does not properly validate characters in nicknames, which allows user-assisted remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted nickname that is not properly handled in a WHO response.

Pidgin: Multiple NULL pointer dereference flaws in Yahoo protocol plug-in

libymsg.c in the Yahoo! protocol plugin in libpurple in Pidgin 2.6.0 through 2.7.10 allows (1) remote authenticated users to cause a denial of service (NULL pointer dereference and application crash) via a malformed YMSG notification packet, and allows (2) remote Yahoo! servers to cause a denial of service (NULL pointer dereference and application crash) via a malformed YMSG SMS message.

Pidgin: MSN DirectConnect DoS (crash) after receiving a short P2P message

directconn.c in the MSN protocol plugin in libpurple 2.7.6 through 2.7.8 in Pidgin before 2.7.9 allows remote authenticated users to cause a denial of service (NULL pointer dereference and application crash) via a short p2pv2 packet in a DirectConnect (aka direct connection) session.

(libpurple): Multiple DoS (crash) flaws by processing of unsanitized Base64 decoder values

libpurple in Pidgin before 2.7.4 does not properly validate the return value of the purple_base64_decode function, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and application crash) via a crafted message, related to the plugins for MSN, MySpaceIM, XMPP, and Yahoo! and the NTLM authentication support.

The notify function in pidgin-knotify.c in the pidgin-knotify plugin 0.2.1 and earlier for Pidgin allows remote attackers to execute arbitrary commands via shell metacharacters in a message.

pidgin: ICQ X-Status denial of service (NULL deref)

The clientautoresp function in family_icbm.c in the oscar protocol plugin in libpurple in Pidgin before 2.7.2 allows remote authenticated users to cause a denial of service (NULL pointer dereference and application crash) via an X-Status message that lacks the expected end tag for a (1) desc or (2) title element.

pidgin: MITM attack possible on non-DNSSEC XMPP connections

An issue was discovered in Pidgin before 2.14.9. A remote attacker who can spoof DNS responses can redirect a client connection to a malicious server. The client will perform TLS certificate verification of the malicious domain name instead of the original XMPP service domain, allowing the attacker to take over control over the XMPP connection and to obtain user credentials and all communication content. This is similar to CVE-2022-24968.

pidgin: Out-of-bounds write in purple_markup_unescape_entity triggered by invalid XML

An out-of-bounds write flaw was found in the way Pidgin before 2.12.0 processed XML content. A malicious remote server could potentially use this flaw to crash Pidgin or execute arbitrary code in the context of the pidgin process.

pidgin: X.509 Certificates Improperly Imported

Pidgin version <2.11.0 contains a vulnerability in X.509 Certificates imports specifically due to improper check of return values from gnutls_x509_crt_init() and gnutls_x509_crt_import() that can result in code execution. This attack appear to be exploitable via custom X.509 certificate from another client. This vulnerability appears to have been fixed in 2.11.0.

pidgin: libpurple no way to restrict "private" messages from being sent over session dbus

Pidgin 2.10.0 uses DBUS for certain cleartext communication, which allows local users to obtain sensitive information via a dbus session monitor.