CVE-2006-1329 in jabberd
Summary
by MITRE
The SASL negotiation in Jabber Studio jabberd before 2.0s11 allows remote attackers to cause a denial of service ("c2s segfault") by sending a "response stanza before an auth stanza".
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Analysis
by VulDB Data Team • 02/02/2025
The vulnerability identified as CVE-2006-1329 affects Jabber Studio jabberd versions prior to 2.0s11, specifically targeting the Simple Authentication and Security Layer implementation during the client-to-server authentication process. This flaw represents a classic protocol violation that exploits improper state handling within the authentication negotiation sequence, creating a condition where the system becomes unstable and ultimately crashes.
The technical exploitation occurs when a remote attacker crafts a malicious XML stanza that violates the expected SASL negotiation flow by sending a response stanza before receiving the corresponding authentication stanza from the server. This sequence disrupts the normal authentication state machine that jabberd employs during SASL authentication, causing the application to enter an undefined state where it attempts to process data in an improper order. The flaw manifests as a segmentation fault within the client-to-server connection handler, leading to an immediate application crash that terminates the service.
From an operational impact perspective, this vulnerability enables a remote attacker to execute a denial of service attack against Jabber Studio jabberd servers without requiring any authentication credentials or privileged access. The service interruption affects all users connected to the affected server, potentially disrupting real-time communication services and messaging infrastructure that depends on the jabberd server. The attack is particularly concerning because it can be executed by any remote user with access to the network, making it a critical vulnerability for any organization relying on this messaging platform.
The vulnerability maps to CWE-248, which describes an "Uncaught Exception" in software systems, where the application fails to properly handle exceptional conditions during the authentication process. From an ATT&CK framework perspective, this represents a denial of service technique that leverages protocol manipulation to exploit implementation weaknesses in the authentication handler. The vulnerability also aligns with ATT&CK technique T1499.004, which covers network denial of service attacks that target specific services or protocols.
Mitigation strategies should prioritize immediate patching of affected jabberd installations to version 2.0s11 or later, which includes proper state validation and error handling for SASL negotiation sequences. Administrators should also implement network-level filtering to restrict unauthorized access to the Jabber server ports and consider implementing intrusion detection systems that can identify anomalous stanza patterns. Additionally, configuring proper logging and monitoring for authentication failures can help detect exploitation attempts and provide forensic evidence for security investigations. The fix typically involves implementing proper state machine validation that ensures all required authentication stanzas are received before processing any response stanzas, preventing the segmentation fault condition that leads to the service crash.