CVE-2014-2743 in Metronome
Summary
by MITRE
plugins/mod_compression.lua in Lightwitch Metronome through 3.4 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.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 05/10/2026
The vulnerability identified as CVE-2014-2743 affects Lightwitch Metronome versions 3.4 and earlier, specifically within the plugins/mod_compression.lua module. This issue represents a significant security flaw that enables remote attackers to exploit the XMPP streaming protocol through malformed compressed XML elements. The vulnerability stems from inadequate input validation and processing restrictions within the compression plugin, creating a pathway for malicious actors to consume excessive system resources.
The technical flaw manifests in the improper handling of compressed XML elements during XMPP stream processing. When a maliciously crafted XMPP stream is received, the compression plugin fails to adequately validate or limit the complexity and size of compressed elements. This allows attackers to construct specially formatted XML data that, when processed through the compression mechanism, causes the server to consume excessive CPU and memory resources. The vulnerability operates at the protocol level, specifically targeting the XML parsing and compression components of the XMPP implementation.
The operational impact of this vulnerability extends beyond simple resource exhaustion, creating a potential denial of service condition that can severely disrupt service availability. Attackers can leverage this weakness to consume system resources at an unsustainable rate, potentially leading to complete service unavailability for legitimate users. The "xmppbomb" moniker reflects the explosive nature of resource consumption that occurs when the malicious stream is processed, as the compression algorithm becomes overwhelmed by malformed input that appears benign but contains excessive nesting or recursive structures.
This vulnerability aligns with CWE-400, which categorizes "Uncontrolled Resource Consumption" as a common weakness in software systems. The flaw demonstrates poor input validation practices and inadequate resource limiting mechanisms within the compression plugin. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers "Endpoint Denial of Service" through resource exhaustion attacks. The attack vector requires only network access to the affected service, making it particularly dangerous as it can be exploited remotely without requiring authentication or elevated privileges.
Mitigation strategies for this vulnerability include immediate patching of Lightwitch Metronome to version 3.5 or later, which contains the necessary fixes for proper XML element validation. Organizations should implement rate limiting and resource consumption monitoring to detect anomalous processing patterns that might indicate exploitation attempts. Additionally, deploying network-level filtering to restrict XMPP traffic and implementing proper input validation at the protocol level can help prevent malicious streams from reaching the vulnerable compression plugin. Security teams should also consider implementing intrusion detection systems that can identify and alert on suspicious XMPP traffic patterns associated with resource exhaustion attacks.