CVE-2008-7070 in KVIrc
Summary
by MITRE
Argument injection vulnerability in the URI handler in KVIrc 3.4.2 Shiny allows remote attackers to execute arbitrary commands via a " (quote) followed by command line switches in a (1) irc:///, (2) irc6:///, (3) ircs:///, or (4) and ircs6:/// URI. NOTE: this might be due to an incomplete fix for CVE-2007-2951.
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Analysis
by VulDB Data Team • 11/11/2024
The CVE-2008-7070 vulnerability represents a critical argument injection flaw in the URI handling mechanism of KVIrc 3.4.2 Shiny, a popular open-source internet relay chat client. This vulnerability specifically targets the application's URI handler component which processes various IRC protocol URIs including irc://, irc6://, ircs://, and ircs6:// schemes. The flaw arises from insufficient input validation and sanitization within the URI parsing logic, creating a pathway for remote attackers to inject malicious command line arguments directly into the application's execution flow.
The technical implementation of this vulnerability exploits the way KVIrc processes URI schemes by failing to properly escape or validate special characters within the URI parameters. When a user clicks on a maliciously crafted URI containing a quote character followed by command line switches, the application's URI handler incorrectly interprets these sequences as legitimate command line arguments rather than part of the URI data. This misinterpretation occurs because the application's argument parsing logic does not adequately distinguish between URI components and actual command line parameters, allowing attackers to inject arbitrary commands that get executed within the context of the application's privileges.
The operational impact of this vulnerability is severe as it enables remote code execution without requiring any user interaction beyond clicking a malicious link. Attackers can craft URIs that, when processed by the vulnerable KVIrc client, execute arbitrary system commands on the victim's machine. This creates a significant attack surface since IRC clients are often used in environments where users may encounter malicious URIs in chat rooms, forums, or email communications. The vulnerability particularly affects users who have KVIrc configured as their default IRC client for handling URI schemes, making the attack vector highly accessible and potentially widespread.
This vulnerability is classified under CWE-74 as "Improper Neutralization of Special Elements in Output Used by a Downstream Component" and specifically relates to CWE-88 as "Argument Injection." The flaw demonstrates characteristics consistent with the attack pattern described in the MITRE ATT&CK framework under T1059.007 for "Command and Scripting Interpreter: Python" and T1059.001 for "Command and Scripting Interpreter: PowerShell" when these commands are executed through shell contexts. The vulnerability represents a regression that may have been introduced due to an incomplete fix for CVE-2007-2951, indicating that the previous remediation efforts were insufficient to fully address the underlying argument injection issue.
Mitigation strategies for this vulnerability involve immediate patching of the KVIrc client to version 3.4.3 or later, which contains proper input validation and sanitization for URI parameters. System administrators should also implement network-level controls such as URI filtering and content validation to prevent users from accessing potentially malicious IRC URIs. Additionally, users should be educated about the risks of clicking unknown or untrusted IRC links, and organizations should consider implementing application whitelisting policies to restrict the execution of potentially vulnerable applications. The fix should ensure that all special characters within URI parameters are properly escaped or encoded before any argument processing occurs, preventing the injection of command line switches that could lead to arbitrary code execution.