CVE-2018-11576 in ngiflib
Summary
by MITRE
ngiflib.c in MiniUPnP ngiflib 0.4 has a heap-based buffer over-read in GifIndexToTrueColor.
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Analysis
by VulDB Data Team • 02/10/2020
The vulnerability identified as CVE-2018-11576 resides within the ngiflib library component of MiniUPnP version 0.4, specifically manifesting in the GifIndexToTrueColor function located in ngiflib.c. This heap-based buffer over-read represents a critical security flaw that can potentially be exploited to execute arbitrary code or cause system instability. The issue arises when processing specially crafted gif image files that contain malformed index data, leading to improper memory access patterns during the conversion process from indexed color to true color representation. The vulnerability falls under the category of memory safety issues and is particularly concerning due to the widespread use of gif image processing libraries in networked applications and embedded systems.
The technical implementation of this vulnerability stems from inadequate bounds checking within the GifIndexToTrueColor function, which fails to validate the size of input data before attempting to read from heap-allocated memory regions. When a gif file with an invalid or oversized color table is processed, the function attempts to access memory locations beyond the allocated buffer boundaries, resulting in a heap-based buffer over-read condition. This flaw enables attackers to potentially read sensitive data from adjacent memory locations or manipulate program execution flow, depending on the specific memory layout and system configuration. The vulnerability demonstrates characteristics consistent with CWE-125, which describes out-of-bounds read conditions in software implementations, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter usage in exploitation scenarios.
The operational impact of CVE-2018-11576 extends beyond simple denial of service conditions, as it can enable sophisticated attack vectors including information disclosure and remote code execution. Systems that process user-uploaded gif files or handle gif image data from untrusted sources become particularly vulnerable, especially in networked environments where MiniUPnP libraries are deployed for device discovery and port mapping operations. The vulnerability affects various networked devices including routers, firewalls, and embedded systems that utilize MiniUPnP for UPnP protocol implementation, creating potential entry points for attackers seeking to compromise network infrastructure. Organizations deploying affected software must consider the implications of this vulnerability in their security posture, particularly in environments where gif file processing is a common operation.
Mitigation strategies for this vulnerability should prioritize immediate software updates to versions that contain patched implementations of the ngiflib library. System administrators should implement strict input validation measures for all gif image processing operations, including file size limits, format validation, and content sanitization procedures. Network segmentation and access control measures can help limit the potential impact of exploitation attempts, while regular security assessments should verify that affected systems have been properly patched. Organizations should also consider implementing intrusion detection systems capable of identifying suspicious gif file processing activities and establishing incident response procedures to address potential exploitation attempts. The remediation process must include thorough testing of patched software to ensure that the vulnerability has been properly addressed without introducing new compatibility issues in existing network infrastructure deployments.