CVE-2018-10847 in Prosody
Summary
by MITRE
prosody before versions 0.10.2, 0.9.14 is vulnerable to an Authentication Bypass. Prosody did not verify that the virtual host associated with a user session remained the same across stream restarts. A user may authenticate to XMPP host A and migrate their authenticated session to XMPP host B of the same Prosody instance.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 04/27/2023
The vulnerability identified as CVE-2018-10847 represents a critical authentication bypass flaw in the Prosody XMPP server software affecting versions prior to 0.10.2 and 0.9.14. This issue stems from inadequate session validation mechanisms that fail to maintain proper host association during stream restarts, creating a fundamental security weakness in the authentication process. The vulnerability specifically targets the XMPP protocol implementation within Prosody, where the server's session management does not adequately verify that users remain authenticated against the same virtual host throughout their session lifecycle.
The technical root cause of this vulnerability lies in the improper handling of stream restarts within the XMPP communication framework. When a user authenticates to a specific virtual host within a Prosody instance, the system should maintain strict association between the user session and the originating host. However, the flaw allows for session migration between different virtual hosts within the same Prosody instance without proper re-authentication. This occurs because the server fails to validate that the virtual host context remains consistent across stream restart operations, effectively permitting unauthorized access to resources that should be restricted to specific host contexts.
The operational impact of this authentication bypass vulnerability is significant and potentially severe for organizations relying on Prosody for instant messaging and real-time communication services. An attacker could exploit this weakness to gain unauthorized access to user sessions and potentially escalate privileges within the XMPP network. The vulnerability enables a form of session hijacking where users authenticated to one virtual host can seamlessly migrate their authenticated sessions to another host within the same instance, effectively bypassing the intended access controls. This could lead to unauthorized access to private conversations, user data, and potentially compromise the entire XMPP service infrastructure.
From a cybersecurity perspective, this vulnerability aligns with CWE-287 which addresses improper authentication issues in software systems. The flaw demonstrates a classic case of insufficient session validation where the system fails to maintain proper state consistency across network operations. The attack vector follows patterns consistent with the ATT&CK framework's privilege escalation techniques, specifically targeting the authentication process to bypass access controls. Organizations using Prosody services face potential exposure to man-in-the-middle attacks, session hijacking, and unauthorized access to sensitive communication channels. The vulnerability affects the integrity and confidentiality of XMPP communications, particularly in environments where multiple virtual hosts are configured within a single Prosody instance, creating a pathway for attackers to traverse host boundaries without proper authentication.
The recommended mitigation strategy involves upgrading to Prosody versions 0.10.2 or 0.9.14, which contain the necessary patches to address the authentication bypass issue. Additionally, system administrators should implement proper monitoring of session activities and host associations to detect anomalous behavior patterns. Network segmentation and access control policies should be strengthened to limit the impact of potential exploitation. Regular security assessments of XMPP implementations are essential to identify similar vulnerabilities in other components of the communication infrastructure. The fix implemented in the patched versions ensures proper validation of virtual host consistency during stream restarts, preventing unauthorized session migration between different host contexts within the same Prosody instance.