CVE-2000-0047 in Pager
Summary
by MITRE
Buffer overflow in Yahoo Pager/Messenger client allows remote attackers to cause a denial of service via a long URL within a message.
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Analysis
by VulDB Data Team • 04/19/2026
The vulnerability identified as CVE-2000-0047 represents a classic buffer overflow flaw within the Yahoo Pager/Messenger client software that was prevalent in the late 1990s and early 2000s. This issue specifically affects the client-side implementation of the messaging protocol where the application fails to properly validate the length of URLs contained within incoming messages. The flaw resides in the manner the client processes and stores URL data, creating a condition where an attacker can craft a malicious message containing an excessively long URL that exceeds the allocated buffer space. This buffer overflow condition occurs when the client attempts to copy or process the malformed URL data without proper bounds checking, leading to memory corruption that can result in application instability.
The technical exploitation of this vulnerability demonstrates a fundamental weakness in input validation and memory management practices that were common in client applications of that era. When the Yahoo Pager/Messenger client receives a message containing a URL that exceeds the predetermined buffer size, the application's memory management routines fail to handle the overflow gracefully, causing the application to crash or behave unpredictably. This behavior aligns with CWE-121, which describes the classic stack-based buffer overflow condition, and represents a precursor to more sophisticated exploitation techniques that would later be refined in the cybersecurity landscape. The vulnerability operates at the application layer and requires no special privileges to exploit, making it particularly dangerous as it can be triggered through simple messaging interactions.
The operational impact of CVE-2000-0047 extends beyond simple denial of service conditions to potentially compromise user experience and system availability within organizations that rely on Yahoo Messenger for communication. When exploited, the vulnerability can cause the client application to terminate unexpectedly, forcing users to restart their messaging sessions and potentially losing unsaved conversations or connection state. In enterprise environments where Yahoo Messenger was commonly used for internal communications, this could result in productivity losses and disruption of business operations. The vulnerability also serves as an early example of how seemingly innocuous data processing operations can become attack vectors when proper security controls are not implemented, highlighting the importance of defensive programming practices.
Mitigation strategies for this vulnerability focus on both immediate application-level fixes and broader architectural improvements in software development practices. The most direct solution involves implementing proper input validation and bounds checking within the client application to ensure that URL data is truncated or rejected if it exceeds predetermined length limits. This approach aligns with the defensive programming principles outlined in the software security community and represents a fundamental requirement for secure coding practices. Organizations should also consider implementing network-level filtering to prevent the transmission of malformed messages that could trigger such vulnerabilities. The ATT&CK framework categorizes this type of vulnerability under the software supply chain attack patterns, emphasizing the need for robust input validation as a core security control. Additionally, regular security updates and patches should be deployed to address similar vulnerabilities in legacy systems, as this flaw represents a common pattern that has been documented in numerous other messaging and communication protocols throughout the years.