CVE-2017-5591 in SleekXMPP
Summary
by MITRE
An incorrect implementation of "XEP-0280: Message Carbons" in multiple XMPP clients allows a remote attacker to impersonate any user, including contacts, in the vulnerable application's display. This allows for various kinds of social engineering attacks. This CVE is for SleekXMPP up to 1.3.1 and Slixmpp all versions up to 1.2.3, as bundled in poezio (0.8 - 0.10) and other products.
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Analysis
by VulDB Data Team • 08/26/2024
The vulnerability described in CVE-2017-5591 represents a critical implementation flaw in XMPP client software that undermines the fundamental security assumptions of instant messaging communications. This issue affects the Message Carbons protocol extension as defined in XEP-0280, which is designed to enable users to receive copies of their own messages across all connected devices. The flaw occurs when clients improperly handle incoming message carbon copies, allowing malicious actors to inject crafted messages that appear to originate from legitimate users within the contact list. This misimplementation creates a trust boundary violation where the application's display layer fails to properly validate message sources, enabling attackers to manipulate the perceived identity of message senders. The vulnerability specifically impacts SleekXMPP versions up to 1.3.1 and Slixmpp versions up to 1.2.3, which are widely distributed in various messaging applications including poezio versions 0.8 through 0.10, making it a pervasive issue across multiple client implementations. The security implications extend beyond simple message manipulation, as this flaw directly violates the principle of authentication and integrity that XMPP clients should maintain for user communications.
The technical execution of this vulnerability relies on the improper handling of XML message stanzas within the Message Carbons implementation. When a client receives a carbon copy message, it should validate that the message originates from the expected user or server and properly authenticate the source before displaying it to the user. However, vulnerable implementations fail to perform adequate source verification, allowing attackers to craft malicious messages that contain spoofed user identifiers and display names. This allows adversaries to manipulate the user interface in real-time, making it appear as though messages are coming from trusted contacts or even administrators within the victim's contact list. The flaw operates at the application layer where message processing occurs, specifically targeting the client-side rendering logic that displays messages to end users. Attackers can exploit this by sending specially crafted carbon copy messages that bypass normal authentication mechanisms, effectively enabling them to impersonate any user within the vulnerable application's context without requiring actual credentials or access to the target user's account. This vulnerability directly maps to CWE-284, which addresses improper access control in software implementations, and also aligns with ATT&CK technique T1566 for social engineering attacks through manipulated communication channels.
The operational impact of CVE-2017-5591 extends far beyond simple impersonation capabilities, creating significant risks for both individual users and organizational communications. Social engineering attacks leveraging this vulnerability can lead to unauthorized information disclosure, as users may be tricked into sharing sensitive data or performing actions based on false message content appearing to come from trusted contacts. The vulnerability enables man-in-the-middle scenarios where attackers can manipulate message flow and content, potentially leading to more sophisticated attacks such as credential harvesting or command execution through deceptive messaging. Organizations relying on XMPP-based communication systems face elevated risks of insider threats and phishing attacks, as the vulnerability undermines the trust model that XMPP clients should maintain between users and their communication interfaces. The widespread distribution of affected software versions across multiple applications means that numerous users could be simultaneously vulnerable, creating a scalable attack surface that can be exploited against large user bases. Additionally, the vulnerability can be combined with other attack vectors to create more complex exploitation scenarios, potentially leading to privilege escalation or access to additional system resources when users interact with the manipulated messages. The impact is particularly severe in environments where XMPP clients are used for business communications, as the manipulation of message displays can compromise operational security and business continuity. This vulnerability represents a significant weakening of the security posture for XMPP-based messaging systems and highlights the critical importance of proper protocol implementation validation in security-sensitive applications.