CVE-2018-7054 in irssi
Summary
by MITRE
An issue was discovered in Irssi before 1.0.7 and 1.1.x before 1.1.1. There is a use-after-free when a server is disconnected during netsplits.
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Analysis
by VulDB Data Team • 02/08/2023
The vulnerability identified as CVE-2018-7054 represents a critical use-after-free condition affecting the Irssi IRC client software. This flaw exists in versions prior to 1.0.7 and 1.1.x before 1.1.1, creating a significant security risk for users who rely on this popular terminal-based IRC client. The issue manifests specifically during network disruption scenarios, particularly when servers disconnect during netsplit events, which are common occurrences in IRC networks where network partitions cause temporary disconnections between server nodes.
The technical root cause of this vulnerability lies in improper memory management within Irssi's handling of server connection states. When a server disconnects during a netsplit event, the software fails to properly release memory resources associated with the connection object before attempting to access or manipulate those freed memory locations. This use-after-free condition occurs because the application continues to reference memory that has already been deallocated, leading to unpredictable behavior and potential code execution exploits. The vulnerability is classified under CWE-416, which specifically addresses the use of freed memory, making it a direct implementation of this well-known memory safety issue.
The operational impact of CVE-2018-7054 extends beyond simple application instability, as it can potentially be exploited by malicious actors to execute arbitrary code on affected systems. During netsplit events, which are inherent to IRC network topology and occur frequently during network congestion or server maintenance, an attacker could manipulate the disconnection sequence to trigger the use-after-free condition. This could result in remote code execution, allowing attackers to gain control of the victim's system, access sensitive communications, or potentially escalate privileges within the network environment. The vulnerability is particularly concerning in environments where Irssi is used for critical communications or as part of security monitoring infrastructure.
Mitigation strategies for this vulnerability require immediate software updates to versions 1.0.7 or 1.1.1 and later, which contain the necessary memory management fixes. System administrators should prioritize patching affected installations and verify that all Irssi instances are running patched versions. Additionally, network monitoring should be enhanced to detect unusual disconnection patterns that might indicate exploitation attempts. Organizations should implement security awareness training for users who operate Irssi in sensitive environments, ensuring they understand the risks associated with network disruption events. The vulnerability aligns with ATT&CK technique T1059.007, which covers command and scripting interpreter usage, as exploitation could enable attackers to execute commands through compromised systems. Regular security assessments and vulnerability scanning should include checks for outdated Irssi installations to prevent exploitation of this and similar memory safety issues that could be leveraged for broader network compromise.