CVE-2007-3612 in Visual IRC
Summary
by MITRE
Stack-based buffer overflow in Visual IRC (ViRC) 2.0 allows remote IRC servers to execute arbitrary code via a long response to a JOIN command.
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Analysis
by VulDB Data Team • 09/24/2024
The vulnerability described in CVE-2007-3612 represents a critical stack-based buffer overflow flaw within Visual IRC version 2.0, a popular internet relay chat client that was widely used in the mid-2000s for real-time communication across irc networks. This vulnerability specifically manifests when the client receives a malformed response from an IRC server during the JOIN command execution process, creating a condition where attacker-controlled data can overwrite adjacent memory locations on the program's stack. The flaw resides in the client's insufficient input validation mechanisms that fail to properly bounds-check the length of data received from remote servers, allowing malicious actors to craft specially formatted responses that exceed the allocated buffer space.
From a technical perspective, the vulnerability operates through a classic stack buffer overflow attack vector where the ViRC application does not perform adequate boundary checking when processing JOIN command responses from IRC servers. The software allocates a fixed-size buffer on the stack to store the response data, but when a remote server sends data exceeding this predetermined limit, the excess bytes overwrite adjacent stack memory including return addresses, saved registers, and other critical program state information. This memory corruption directly enables attackers to manipulate the program's execution flow and potentially execute arbitrary code with the privileges of the affected user. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which is a well-documented weakness in software development practices that violates fundamental security principles of input validation and memory management.
The operational impact of this vulnerability extends beyond simple code execution, as it provides remote attackers with complete system compromise capabilities when successfully exploited. An attacker who controls an IRC server or can intercept traffic between the client and legitimate servers can craft malicious JOIN responses that trigger the buffer overflow condition, potentially leading to unauthorized access, data theft, system takeover, or further network propagation. The attack requires minimal sophistication as it only necessitates the ability to send specially crafted responses to a vulnerable client, making it particularly dangerous in environments where users connect to multiple IRC networks or where the client is used in enterprise settings. The vulnerability's remote nature means that attackers do not need physical access to the target system and can exploit it from anywhere on the internet.
Security mitigations for this vulnerability should focus on immediate patching and deployment of the vendor's security update that addresses the buffer overflow condition through proper bounds checking and input validation. System administrators should also implement network-level protections such as firewall rules that limit IRC traffic to trusted servers, though this approach is less effective given that the vulnerability can be triggered by any remote IRC server. From a defensive standpoint, the vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation would likely involve executing malicious code through the compromised client application. Additionally, implementing application whitelisting policies that restrict which IRC clients can be executed, combined with regular security audits of network communications, would provide layered protection against similar vulnerabilities in other applications. The incident underscores the critical importance of proper input validation and memory safety practices in client applications that process untrusted network data, particularly those operating in distributed network environments where trust relationships may be compromised.