CVE-2003-0235 in ICQ
Summary
by MITRE
Format string vulnerability in POP3 client for Mirabilis ICQ Pro 2003a allows remote malicious servers to execute arbitrary code via format strings in the response to a UIDL command.
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Analysis
by VulDB Data Team • 01/11/2019
The vulnerability identified as CVE-2003-0235 represents a critical format string flaw within the POP3 client implementation of Mirabilis ICQ Pro 2003a software. This weakness specifically manifests when the client processes responses to UIDL commands received from remote POP3 servers, creating an exploitable condition that can be leveraged by malicious actors to execute arbitrary code on vulnerable systems. The vulnerability stems from improper input validation and handling of format specifiers within the client's response parsing logic, which fails to adequately sanitize or escape user-supplied data before processing.
The technical exploitation of this vulnerability occurs through carefully crafted responses from malicious POP3 servers that contain format string specifiers such as %s, %d, or %x within the UIDL command responses. When the vulnerable ICQ client processes these malformed responses, the format string vulnerability allows attackers to manipulate the program's execution flow by injecting malicious format specifiers that can read from or write to memory locations. This type of vulnerability falls under the CWE-134 classification of "Use of Externally-Controlled Format String" and aligns with the broader category of injection flaws that have been consistently identified as high-risk security weaknesses in software applications. The attack vector specifically targets the client-side POP3 processing functionality, where the application fails to properly validate or escape format specifiers in server responses, creating opportunities for memory corruption and code execution.
The operational impact of this vulnerability extends beyond simple privilege escalation or denial of service conditions, as it provides attackers with the capability to execute arbitrary code with the privileges of the affected user account. This presents a significant risk to enterprise environments where ICQ Pro users may be connected to untrusted or compromised POP3 servers, potentially allowing attackers to gain persistent access to systems, escalate privileges, or establish backdoors. The vulnerability affects the confidentiality, integrity, and availability of the targeted systems, as successful exploitation could lead to complete system compromise. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1190 "Exploit Public-Facing Application" and T1059.007 "Command and Scripting Interpreter: PowerShell" when considering the potential for command execution and lateral movement.
Mitigation strategies for CVE-2003-0235 should prioritize immediate software updates and patches from the vendor, as the vulnerability has been addressed through proper input validation and format string handling in subsequent releases. Organizations should implement network segmentation to limit exposure to untrusted POP3 servers and consider disabling POP3 functionality if not essential for business operations. Security monitoring should focus on detecting anomalous POP3 server responses and unusual client behavior that may indicate exploitation attempts. Additionally, implementing proper input validation and sanitization practices in client applications, particularly those handling external data inputs, can prevent similar vulnerabilities from occurring in other software components. The vulnerability serves as a reminder of the importance of proper memory management and input validation in client-side applications, particularly those that process untrusted network data, and demonstrates how seemingly minor implementation flaws can result in significant security consequences.