CVE-2004-2391 in Gadu-Gadu Transport
Summary
by MITRE
Jabber Gadu-Gadu Transport (a.k.a. jabber-gg-transport) 2.0.x before 2.0.8 allows remote attackers to cause a denial of service a message with an empty <priority/> tag.
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Analysis
by VulDB Data Team • 06/23/2018
The Jabber Gadu-Gadu Transport represents a component within instant messaging infrastructure that facilitates communication between Jabber/XMPP protocol clients and Gadu-Gadu messaging service users. This transport mechanism serves as a bridge enabling interoperability between different messaging protocols, allowing users to communicate across disparate messaging platforms. The vulnerability affects versions 2.0.x prior to 2.0.8, indicating a specific regression or oversight in the software's handling of incoming XML messages that could be exploited by remote attackers to disrupt service availability.
The technical flaw manifests through improper validation of XML message structures, specifically when processing the <priority/> tag element within incoming messages. This particular XML element should contain a numeric value indicating message priority levels, but the vulnerable implementation fails to properly validate or sanitize empty tag occurrences. When an attacker sends a malformed message containing an empty <priority/> tag, the transport service processes this input without adequate error handling, leading to a crash or service disruption. This represents a classic example of insufficient input validation and error handling within XML processing components.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the availability of messaging services for legitimate users. Remote attackers can exploit this weakness without requiring authentication or privileged access, making it particularly dangerous in production environments where continuous service availability is critical. The denial of service condition can be achieved through a single malicious message, making it an attractive vector for attackers seeking to disrupt communications. This vulnerability directly impacts the reliability and trustworthiness of messaging infrastructure components, potentially affecting business communications and user productivity.
Security mitigations for this vulnerability involve applying the vendor-provided patch version 2.0.8 or later, which implements proper XML validation and error handling for the priority tag element. System administrators should also implement monitoring and intrusion detection mechanisms to identify unusual message patterns that might indicate exploitation attempts. Additionally, implementing proper input sanitization and validation procedures for all XML processing components helps prevent similar issues. This vulnerability aligns with CWE-20, which addresses improper input validation, and represents a common pattern in messaging systems where XML parsing components lack adequate defensive programming practices. The attack vector corresponds to techniques described in the MITRE ATT&CK framework under service disruption and availability compromise tactics, emphasizing the importance of robust input validation in protocol implementations.