CVE-2016-1925 in LHA
Summary
by MITRE
Integer underflow in header.c in lha allows remote attackers to have unspecified impact via a large header size value for the (1) level0 or (2) level1 header in a lha archive, which triggers a buffer overflow.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 05/14/2026
The vulnerability identified as CVE-2016-1925 represents a critical integer underflow condition within the header.c component of the lha archiving utility, a widely used tool for handling lha format archives. This flaw occurs when processing archive headers where the software fails to properly validate header size values, specifically affecting level0 and level1 header structures. The integer underflow manifests when a maliciously crafted archive contains an excessively large header size value that, when processed, results in a negative integer value due to unsigned integer arithmetic overflow. This condition directly leads to a subsequent buffer overflow scenario where the software attempts to allocate memory based on the corrupted size value, creating opportunities for memory corruption and arbitrary code execution.
The technical implementation of this vulnerability aligns with CWE-190, which describes integer overflow and underflow conditions that can result in memory corruption. When lha processes an archive with an oversized header size, the software's internal buffer allocation logic fails to account for the underflow condition, causing the system to allocate insufficient memory for the intended buffer operations. This misalignment between expected and actual buffer sizes creates a predictable memory corruption pattern that attackers can exploit to overwrite adjacent memory locations. The vulnerability is particularly dangerous because it operates at the archive parsing layer, meaning any application or system that utilizes lha for archive extraction becomes a potential target for remote exploitation.
The operational impact of CVE-2016-1925 extends across multiple attack vectors and system configurations where lha archives are processed. Remote attackers can craft malicious archives that trigger this vulnerability during normal archive extraction operations, potentially leading to complete system compromise when the affected software executes with elevated privileges. The vulnerability is especially concerning in automated processing environments such as web applications that accept user-uploaded archives, email servers processing archive attachments, or content delivery systems that handle lha files. According to ATT&CK framework, this vulnerability maps to T1203 - Exploitation for Client Execution, where adversaries leverage software vulnerabilities to execute arbitrary code on target systems. The attack surface is broad since lha is commonly used in various operating systems and applications, making the exploitation potential widespread across different computing environments.
Mitigation strategies for CVE-2016-1925 should focus on both immediate patching and operational security measures. The primary solution involves updating to lha versions that have implemented proper input validation and integer overflow protection mechanisms. Organizations should also implement defensive programming practices such as validating all header size values before processing, implementing bounds checking for buffer allocations, and using safe integer arithmetic operations. Additionally, network segmentation and access controls should limit exposure to systems that process lha archives, particularly those that automatically extract user-uploaded content. Security monitoring should include detection of suspicious archive file patterns and unusual processing behaviors that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of input validation and proper error handling in archive processing utilities, highlighting how seemingly simple parsing operations can create complex security risks when not properly secured against malformed input data.