msg.c in the MSN protocol plugin in libpurple in Pidgin before 2.10.4 does not properly handle crafted characters, which allows remote servers to cause a denial of service (application crash) by placing these characters in a text/plain message.

proxy.c in libpurple in Pidgin before 2.10.4 does not properly handle canceled SOCKS5 connection attempts, which allows user-assisted remote authenticated users to cause a denial of service (application crash) via a sequence of XMPP file-transfer requests.

The pidgin_conv_chat_rename_user function in gtkconv.c in Pidgin before 2.10.2 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) by changing a nickname while in an XMPP chat room.

The msn_oim_report_to_user function in oim.c in the MSN protocol plugin in libpurple in Pidgin before 2.10.2 allows remote servers to cause a denial of service (application crash) via an OIM message that lacks UTF-8 encoding.

family_feedbag.c in the oscar protocol plugin in libpurple in Pidgin before 2.10.1 does not perform the expected UTF-8 validation on message data, which allows remote attackers to cause a denial of service (application crash) via a crafted (1) AIM or (2) ICQ message associated with buddy-list addition.

The silc_channel_message function in ops.c in the SILC protocol plugin in libpurple in Pidgin before 2.10.1 does not perform the expected UTF-8 validation on message data, which allows remote attackers to cause a denial of service (application crash) via a crafted message, a different vulnerability than CVE-2011-3594.

The XMPP protocol plugin in libpurple in Pidgin before 2.10.1 does not properly handle missing fields in (1) voice-chat and (2) video-chat stanzas, which allows remote attackers to cause a denial of service (application crash) via a crafted message.

The g_markup_escape_text function in the SILC protocol plug-in in libpurple 2.10.0 and earlier, as used in Pidgin and possibly other products, allows remote attackers to cause a denial of service (crash) via invalid UTF-8 sequences that trigger use of invalid pointers and an out-of-bounds read, related to interactions with certain versions of glib2.

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.

The msn_httpconn_parse_data function in httpconn.c in the MSN protocol plugin in libpurple in Pidgin before 2.10.0 does not properly handle HTTP 100 responses, which allows remote attackers to cause a denial of service (incorrect memory access and application crash) via vectors involving a crafted server message.