CVE-2014-2745 in Prosody
Summary
by MITRE
Prosody before 0.9.4 does not properly restrict the processing of compressed XML elements, which allows remote attackers to cause a denial of service (resource consumption) via a crafted XMPP stream, aka an "xmppbomb" attack, related to core/portmanager.lua and util/xmppstream.lua.
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Analysis
by VulDB Data Team • 05/10/2026
The vulnerability identified as CVE-2014-2745 affects Prosody versions prior to 0.9.4 and represents a critical denial of service flaw that exploits improper handling of compressed XML elements within XMPP streams. This vulnerability specifically targets the core/portmanager.lua and util/xmppstream.lua components of the Prosody XMPP server implementation, creating a scenario where remote attackers can manipulate the processing of compressed XML data to consume excessive system resources. The flaw enables what security researchers categorize as an "xmppbomb" attack pattern, where maliciously crafted XMPP streams can trigger resource exhaustion conditions that effectively disable the targeted server's ability to process legitimate communications.
The technical mechanism behind this vulnerability involves the insufficient validation and restriction of compressed XML elements during XMPP stream processing. When Prosody receives a crafted XMPP stream containing specially constructed compressed XML data, the server fails to properly limit the processing of these elements, leading to exponential resource consumption patterns. This behavior stems from inadequate input validation within the XML parsing routines, particularly in how the software handles compressed data structures that can be recursively expanded or nested in ways that cause memory allocation to spiral out of control. The vulnerability manifests as a resource exhaustion condition that can be triggered through a single malicious XMPP stream, making it particularly dangerous for systems that process untrusted XMPP traffic.
From an operational impact perspective, this vulnerability creates significant risks for organizations relying on Prosody as their XMPP server infrastructure. The denial of service condition can render the entire XMPP service unavailable to legitimate users, disrupting real-time communication services, instant messaging capabilities, and any applications that depend on XMPP for messaging and presence information. The attack can be executed remotely without requiring authentication or specific privileges, making it an attractive vector for malicious actors seeking to disrupt services. The resource consumption pattern typically affects memory usage and CPU processing cycles, potentially causing system instability, crashes, or complete service outages that can persist until the affected server is manually restarted or the malicious stream is detected and filtered.
Organizations should implement immediate mitigations including upgrading to Prosody version 0.9.4 or later, which contains the necessary patches to properly restrict compressed XML element processing. Network-level defenses such as rate limiting and traffic filtering can help reduce the impact of such attacks by limiting the volume of compressed XML data that can be processed within a given time period. Additionally, implementing proper input validation and sanitization measures within XMPP stream processing components can provide defense-in-depth protection against similar vulnerabilities. Security teams should monitor for indicators of compromise related to XMPP bomb attacks and establish incident response procedures specifically addressing resource exhaustion conditions in XMPP server environments. This vulnerability aligns with CWE-400, which addresses "Uncontrolled Resource Consumption," and represents a classic example of how improper input handling can lead to denial of service conditions that affect critical communication infrastructure.
The broader implications of this vulnerability extend to XMPP ecosystem security, as it demonstrates how compressed data handling can create exponential resource consumption patterns that are difficult to detect and prevent through traditional security measures. System administrators should consider implementing automated monitoring for unusual resource usage patterns that could indicate exploitation attempts, while also ensuring that XMPP server configurations properly enforce resource limits and timeouts for stream processing operations. The vulnerability serves as a reminder of the importance of proper XML processing validation and the need for robust input sanitization in communication protocol implementations. Organizations using Prosody or similar XMPP server software should conduct comprehensive security assessments to identify and remediate similar vulnerabilities that might exist in other components of their communication infrastructure, particularly those involving data compression and parsing operations that could be similarly abused to consume system resources.