Pidgin MXIT Contact Mood Denial of Service Vulnerability(CVE-2016-2373)

### DESCRIPTION A denial of service vulnerability exists in the handling of the MXIT protocol in Pidgin. Specially crafted MXIT data sent via the server could potentially result in an out-of-bounds read. A malicious server or user can send an invalid mood to trigger this vulnerability. ### CVSSv3 SCORE 5.9 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H ### TESTED VERSIONS Pidgin 2.10.11 ### PRODUCT URLs https://www.pidgin.im/ ### DETAILS In the function mxitparsecmd_contact in mxit/protocol.c at line 1743 contact->mood will be read from data coming from the server when parsing a contact update packet. ``` 1743 contact->mood = atoi( rec->fields[5]->data ); ``` At line 1759, this mood will be passed to the function mxitupdatecontact(): ``` 1759 mxit_update_contact( session, contact ); ``` This function is defined in mxit/roster.c at line 363. If mood is anything other than 0, then this value is subsequently used to as index into the mxit_moods array at line 432. ``` 432 purple_prpl_got_user_status( session->acc, contact->username, "mood", PURPLE_MOOD_NAME, mxit_moods[contact->mood-1].mood, NULL ); ``` This can result in an out-of-bounds read of this information, potentially resulting in a crash of the program if that memory location is not accessible. ### TIMELINE * 2016-04-13 - Vendor Notification * 2016-06-21 - Public Disclosure