CVE-2003-0129 in Evolution
Summary
by MITRE
Ximian Evolution Mail User Agent 1.2.2 and earlier allows remote attackers to cause a denial of service (memory consumption) via a mail message that is uuencoded multiple times.
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Analysis
by VulDB Data Team • 12/15/2024
The vulnerability identified as CVE-2003-0129 represents a significant denial of service weakness in Ximian Evolution Mail User Agent version 1.2.2 and earlier. This flaw specifically targets the mail processing capabilities of the application, creating a condition where maliciously crafted email messages can trigger excessive memory consumption. The vulnerability operates through a technique known as nested uuencoding, where a single email message contains multiple layers of uuencoded data that must be processed sequentially by the mail client.
The technical mechanism behind this vulnerability stems from the Evolution MUA's inadequate handling of recursive uuencoding operations. When the application encounters a uuencoded message, it attempts to decode the content in a manner that does not properly account for multiple nested encoding layers. Each decoding operation consumes additional memory resources as the application maintains state information for the decoding process. As the number of nested uuencoding layers increases, the memory consumption grows exponentially rather than linearly, leading to resource exhaustion that ultimately results in application instability or complete system crash.
This vulnerability has substantial operational impact within email security contexts, particularly in environments where automated email processing or mail servers handle large volumes of incoming messages. The denial of service condition can be exploited by remote attackers without requiring authentication, making it particularly dangerous in public email systems or shared hosting environments. The memory consumption pattern follows a predictable but potentially devastating trajectory that can cause system-wide performance degradation or complete service interruption, affecting not just individual users but entire email infrastructure components.
From a cybersecurity perspective, this vulnerability aligns with CWE-400, which addresses "Uncontrolled Resource Consumption," and demonstrates characteristics consistent with attack patterns found in the ATT&CK framework under the T1499 category for "Network Denial of Service." The vulnerability also reflects poor input validation practices that have become increasingly common in legacy email applications. Organizations should implement immediate mitigations including updating to patched versions of Evolution MUA, implementing email filtering rules that detect and block nested uuencoded content, and establishing memory monitoring systems to detect abnormal resource consumption patterns. Additionally, network administrators should consider implementing rate limiting and connection throttling mechanisms to prevent exploitation attempts and maintain system availability during potential attack scenarios.