CVE-2004-1688 in Pigeon Server
Summary
by MITRE
Pigeon Server 3.02.0143 and earlier allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a long login name sent to port 3103.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 08/03/2025
The vulnerability identified as CVE-2004-1688 affects Pigeon Server versions 3.02.0143 and earlier, presenting a significant security risk through a carefully crafted denial of service attack. This flaw specifically targets the server's authentication mechanism on port 3103, where an attacker can exploit a buffer handling issue to trigger system instability. The vulnerability operates by sending an excessively long login name to the server, which causes the authentication process to enter an infinite loop, resulting in sustained high CPU utilization that effectively renders the service unavailable to legitimate users.
The technical root cause of this vulnerability lies in the server's insufficient input validation and improper buffer management during the login process. When a login name exceeding the expected length is transmitted, the server's parsing logic fails to properly handle the overflow condition, leading to a condition where the authentication routine continuously loops without proper termination. This behavior directly maps to CWE-129, which addresses improper validation of length of input buffers, and CWE-674, which covers uncontrolled recursion in software. The server's failure to implement proper bounds checking and input sanitization creates an exploitable condition where attacker-controlled data can manipulate the program flow into an infinite loop state.
From an operational perspective, this vulnerability presents a severe threat to service availability and system stability. The infinite loop consumes substantial CPU resources, potentially causing the server to become unresponsive or crash entirely, thereby disrupting legitimate user access and service continuity. Attackers can exploit this weakness with minimal technical skill by simply crafting a sufficiently long login string, making it particularly dangerous in environments where service availability is critical. The impact extends beyond simple disruption as the sustained high CPU usage can affect other system processes and potentially trigger cascading failures in dependent services. This vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates how seemingly simple input validation flaws can create substantial operational impacts.
The recommended mitigation strategies include implementing immediate software updates to patch the vulnerable Pigeon Server versions, applying input length restrictions on authentication parameters, and configuring proper rate limiting mechanisms to prevent abuse of the authentication endpoint. System administrators should also implement monitoring solutions to detect unusual CPU consumption patterns and establish proper access controls to limit exposure. Additionally, network segmentation and firewall rules can be configured to restrict access to port 3103 from untrusted networks, reducing the attack surface. The vulnerability highlights the critical importance of input validation and buffer management in server applications, serving as a reminder of how fundamental security practices can prevent widespread service disruption. Organizations should also consider implementing intrusion detection systems to monitor for patterns consistent with this type of denial of service attack and establish incident response procedures for rapid remediation of such vulnerabilities.