CVE-2016-9928 in MCabber
Summary
by MITRE
MCabber before 1.0.4 is vulnerable to roster push attacks, which allows remote attackers to intercept communications, or add themselves as an entity on a 3rd party's roster as another user, which will also garner associated privileges, via crafted XMPP packets.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 11/08/2024
The vulnerability identified as CVE-2016-9928 affects MCabber versions prior to 1.0.4, representing a critical security flaw in instant messaging client software that operates over the Extensible Messaging and Presence Protocol. This vulnerability specifically targets the roster management functionality within XMPP implementations, where the client maintains a list of contacts and their associated privileges. The flaw allows remote attackers to exploit the roster push mechanism, which is designed to synchronize contact lists between XMPP clients and servers, creating a dangerous attack vector that undermines the fundamental security assumptions of instant messaging communications.
The technical implementation of this vulnerability stems from insufficient validation of roster push packets received from external sources. When MCabber processes roster updates, it fails to properly authenticate or verify the legitimacy of the source sending these packets, allowing malicious actors to inject crafted XMPP messages that modify the recipient's contact list. This weakness enables attackers to either intercept communications by positioning themselves within the communication chain or to add themselves to another user's roster with forged identities. The vulnerability specifically relates to CWE-284, which addresses improper access control mechanisms, and falls under the broader category of privilege escalation vulnerabilities where attackers can manipulate access control lists to gain unauthorized privileges.
The operational impact of this vulnerability extends beyond simple privacy violations to encompass significant security risks in enterprise and personal communication environments. An attacker who successfully exploits this vulnerability can establish persistent presence on a victim's roster, potentially gaining access to sensitive information exchanges, impersonating legitimate users, or creating backdoors for future attacks. The ability to add oneself as another user's contact also enables privilege escalation, as the attacker's entry may be granted the same access levels and permissions as legitimate roster entries. This vulnerability directly impacts the confidentiality and integrity of communications, as it allows for man-in-the-middle attacks where the attacker can intercept and potentially modify messages between parties who believe they are communicating with legitimate contacts.
Mitigation strategies for CVE-2016-9928 require immediate software updates to MCabber version 1.0.4 or later, which includes proper roster validation and authentication mechanisms. Organizations should also implement network-level controls such as firewalls that restrict XMPP traffic to trusted sources, and consider deploying XMPP server configurations that enforce stricter roster management policies. The ATT&CK framework categorizes this vulnerability under T1190 - Exploit Public-Facing Application, where attackers leverage insecure roster handling to establish persistent access. Additional defensive measures include implementing network monitoring to detect anomalous roster update patterns, enforcing secure XMPP configurations, and conducting regular security assessments of instant messaging infrastructure. Security teams should also establish incident response procedures specifically addressing roster-based attacks and ensure that all XMPP clients are regularly updated to prevent exploitation of known vulnerabilities.