CVE-2021-44568 in libsolv
Summary
by MITRE • 02/21/2022
Two heap-overflow vulnerabilities exist in openSUSE/libsolv libsolv through 13 Dec 2020 in the decisionmap variable via the resolve_dependencies function at src/solver.c (line 1940 & line 1995), which could cause a remote Denial of Service.
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Analysis
by VulDB Data Team • 02/25/2022
The heap-overflow vulnerabilities identified in openSUSE/libsolv libsolv represent critical memory safety issues that can be exploited to cause remote denial of service conditions. These flaws exist within the decisionmap variable handling mechanism of the resolve_dependencies function in the src/solver.c source file, specifically manifesting at lines 1940 and 1995. The vulnerability stems from improper bounds checking and memory allocation handling when processing dependency resolution requests, creating opportunities for attackers to manipulate memory structures through crafted inputs.
The technical implementation of these heap overflows occurs during the dependency resolution process where the decisionmap variable is manipulated without adequate validation of input parameters. When maliciously crafted dependency data is processed through the resolve_dependencies function, the memory allocation routines fail to properly verify array bounds, allowing attackers to write beyond allocated memory regions. This memory corruption can result in program crashes, unpredictable behavior, and complete system unavailability. The vulnerability is particularly concerning because it operates at the core dependency resolution engine that many package management systems rely upon, making it a prime target for exploitation in automated attack scenarios.
From an operational standpoint, these heap overflows present significant risks to system stability and availability across environments that utilize libsolv for package management operations. The remote denial of service capability means that attackers can potentially disrupt services by sending malformed dependency requests to systems running vulnerable versions of libsolv. This affects not only individual systems but also broader infrastructure that depends on consistent package management functionality. The impact extends beyond simple service interruption to potentially compromise entire software supply chains that rely on stable dependency resolution mechanisms.
The vulnerability aligns with CWE-121, heap-based buffer overflow, and demonstrates characteristics consistent with ATT&CK technique T1499.004, Network Denial of Service, where adversaries leverage memory corruption vulnerabilities to exhaust system resources or cause application crashes. Organizations using affected versions of libsolv should prioritize immediate patching and implementation of input validation measures. Recommended mitigations include upgrading to patched versions of libsolv, implementing strict input validation for dependency data, and deploying network segmentation to limit exposure to potential attackers. Additionally, monitoring systems should be configured to detect anomalous dependency resolution patterns that may indicate exploitation attempts, while maintaining regular security updates to prevent similar vulnerabilities from emerging in related components.