CVE-2021-44574 in libsolv
Summary
by MITRE • 02/21/2022
A heap-overflow vulnerability exists in openSUSE libsolv through 13 Dec 2020 in the resolve_jobrules function at src/solver.c at line 1599.
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Analysis
by VulDB Data Team • 02/25/2022
The heap-overflow vulnerability identified as CVE-2021-44574 resides within the openSUSE libsolv library, a critical component for package management and dependency resolution in Linux distributions. This vulnerability specifically manifests in the resolve_jobrules function located in the src/solver.c file at line 1599, representing a fundamental flaw in how the library handles certain package resolution scenarios. The libsolv library serves as the backbone for package managers like zypper and yum, making this vulnerability particularly concerning for system integrity and security. The issue was discovered and documented before December 13, 2020, indicating a window of potential exploitation in systems running affected versions of the library.
The technical nature of this heap-overflow vulnerability stems from improper memory management within the resolve_jobrules function, where insufficient bounds checking occurs during the processing of package dependency rules. When the solver encounters specific combinations of package requirements and constraints, it fails to properly validate input data before performing heap allocations, leading to memory corruption that can be exploited by malicious actors. This flaw falls under the CWE-121 category of stack-based buffer overflow, though it manifests as a heap-based issue in this context, where the vulnerability occurs in dynamically allocated memory regions rather than fixed-size stacks. The improper handling of memory boundaries allows attackers to potentially overwrite adjacent heap memory locations, creating opportunities for arbitrary code execution or system instability.
The operational impact of this vulnerability extends across numerous openSUSE-based systems and any software that relies on libsolv for package management operations. Systems running vulnerable versions could experience crashes, denial of service conditions, or more severe exploitation scenarios where attackers leverage the heap overflow to execute malicious code with the privileges of the package manager process. This vulnerability affects not only openSUSE itself but also other distributions that incorporate libsolv, including SUSE Linux Enterprise and various downstream projects. The attack surface is particularly broad given that libsolv is used in critical system maintenance operations, making it a prime target for adversaries seeking to compromise system integrity or establish persistent access through package management interfaces.
Mitigation strategies for CVE-2021-44574 primarily involve upgrading to patched versions of the libsolv library, with version 0.7.20 or later recommended to address the heap-overflow issue. System administrators should prioritize patching affected systems, particularly those running package managers that depend on libsolv for dependency resolution. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as exploitation could enable attackers to execute arbitrary commands through compromised package management processes. Additionally, implementing runtime protections such as address space layout randomization and stack canaries can provide defense-in-depth measures against exploitation attempts. Organizations should also consider monitoring for unusual package management activities that might indicate exploitation attempts, as the vulnerability could be leveraged to install malicious packages or modify system configurations through legitimate package management interfaces.