CVE-2017-7191 in irssi
Summary
by MITRE
The netjoin processing in Irssi 1.x before 1.0.2 allows attackers to cause a denial of service (use-after-free) and possibly execute arbitrary code via unspecified vectors.
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Analysis
by VulDB Data Team • 11/22/2022
The vulnerability identified as CVE-2017-7191 affects Irssi versions 1.x prior to 1.0.2 and represents a critical security flaw in the network join processing functionality. This issue manifests as a use-after-free condition that can be exploited by remote attackers to potentially execute arbitrary code or cause denial of service within the affected software environment. The vulnerability stems from improper memory management during the netjoin processing operations, where freed memory locations are accessed after being deallocated, creating opportunities for malicious exploitation.
The technical nature of this vulnerability places it squarely within the CWE-416 category of use-after-free conditions, which occurs when a program continues to reference memory after it has been freed by the system. This particular flaw exists in the network join processing subsystem of Irssi, which handles connection establishment and network communication operations. Attackers can craft malicious network join requests or connection sequences that trigger the improper memory handling, leading to either immediate system instability or more sophisticated exploitation techniques that leverage the freed memory for code execution.
From an operational impact perspective, this vulnerability creates significant risk for users who rely on Irssi for chat network communications and IRC client operations. The denial of service aspect means that legitimate users may experience service interruptions, while the potential for arbitrary code execution opens the door to complete system compromise. The vulnerability affects the core functionality of Irssi's network processing capabilities, making it particularly dangerous for users who depend on continuous connectivity and secure communications within IRC environments.
The exploitation of this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as attackers could potentially leverage the arbitrary code execution capability to establish persistent access or escalate privileges. Organizations and individuals using Irssi should immediately implement mitigation strategies including updating to version 1.0.2 or later, which contains the necessary memory management fixes. Additionally, network segmentation and access controls should be implemented to limit exposure, while monitoring systems should be configured to detect anomalous network join patterns that might indicate exploitation attempts.
This vulnerability demonstrates the critical importance of proper memory management in network applications and highlights how seemingly routine operations like network joining can become attack vectors when memory safety is not properly maintained. The security community has recognized this as a high-severity issue requiring immediate attention, particularly given Irssi's widespread use in both personal and enterprise IRC communications environments. System administrators should prioritize patching this vulnerability across all affected installations to prevent potential exploitation and maintain the integrity of their communication infrastructure.