CVE-2017-15228 in irssi
Summary
by MITRE
Irssi before 1.0.5, when installing themes with unterminated colour formatting sequences, may access data beyond the end of the string.
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Analysis
by VulDB Data Team • 01/04/2023
This vulnerability exists in Irssi version 1.0.5 and earlier, where the application fails to properly handle color formatting sequences during theme installation processes. The flaw occurs when users attempt to install themes containing unterminated color formatting sequences, which causes the application to access memory locations beyond the intended string boundaries. This represents a classic buffer over-read condition that can potentially lead to arbitrary code execution or information disclosure. The vulnerability stems from inadequate input validation and memory management within the color formatting parser, which does not properly terminate or sanitize color codes before processing them. According to CWE-125, this issue falls under the category of "Out-of-bounds Read" where an application reads data past the end of a valid buffer. The problem manifests specifically during theme installation when the application processes color codes that lack proper termination characters, leading to unpredictable memory access patterns.
The operational impact of this vulnerability extends beyond simple memory corruption, as it can be exploited by malicious actors who craft specially formatted themes to trigger the buffer over-read condition. When an unsuspecting user installs a malicious theme, the application's color formatting engine processes the unterminated sequences and accesses adjacent memory regions, potentially exposing sensitive data or allowing attackers to execute arbitrary code. This vulnerability aligns with ATT&CK technique T1059.007 for execution through script-based languages and T1068 for privilege escalation through local exploitation. The memory access violations can result in application crashes, data leakage, or more severe consequences depending on the memory layout and system configuration. Attackers could leverage this issue to gain unauthorized access to system resources or to perform information gathering activities that could aid in further exploitation attempts.
Mitigation strategies for this vulnerability include immediate upgrading to Irssi version 1.0.5 or later, which contains the necessary patches to properly handle unterminated color formatting sequences. System administrators should also implement strict theme validation policies that prevent installation of untrusted themes and establish monitoring procedures to detect unusual memory access patterns. The fix implemented in the patched versions involves enhanced input sanitization and proper bounds checking within the color formatting parser to ensure that all color codes are properly terminated before processing. Additional defensive measures include implementing application sandboxing, restricting theme installation permissions, and conducting regular security audits of third-party themes. Organizations should also consider deploying intrusion detection systems that can identify suspicious memory access patterns and network-based attacks that may exploit this vulnerability. The vulnerability demonstrates the importance of proper input validation and memory management in client-side applications, particularly those that process user-provided content such as themes and configuration files.