CVE-2021-44573 in libsolv
Summary
by MITRE • 02/21/2022
Two heap overflow vulnerabilities exist in oenSUSE libsolv through 13 Dec 2020 in the resolve_installed function at src/solver.c: line 1728 & 1766.
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Analysis
by VulDB Data Team • 02/25/2022
The heap overflow vulnerabilities identified in oenSUSE libsolv represent critical security flaws that can lead to arbitrary code execution and system compromise. These vulnerabilities were discovered in the resolve_installed function within the solver.c source file, specifically at lines 1728 and 1766, affecting versions released through December 13, 2020. The libsolv library serves as a core dependency for package management systems in openSUSE and other distributions, making these vulnerabilities particularly concerning for system integrity and security.
The technical nature of these heap overflows stems from insufficient input validation and memory management within the package resolution algorithm. When the resolve_installed function processes package dependencies and constraints, it fails to properly bounds-check array accesses and memory allocations, allowing attackers to craft malicious package metadata that triggers buffer overflows. The vulnerabilities occur during the resolution of installed packages where the library attempts to manage complex dependency graphs and constraint satisfaction problems. These memory corruption issues manifest when the software writes data beyond the allocated heap memory boundaries, potentially corrupting adjacent memory regions and enabling attackers to manipulate program execution flow.
The operational impact of these vulnerabilities extends beyond simple memory corruption, as they can be exploited to achieve arbitrary code execution on affected systems. Attackers could leverage these flaws by constructing specially crafted package repositories or manipulating existing package metadata to trigger the overflow conditions. The implications are severe for system administrators and users who rely on package management systems, as successful exploitation could result in complete system compromise, privilege escalation, or denial of service conditions. Given that libsolv is integral to package management workflows across multiple distributions, the attack surface is substantial, potentially affecting numerous enterprise and consumer systems.
Mitigation strategies for these heap overflow vulnerabilities should prioritize immediate patching of affected libsolv versions, with particular attention to the specific lines mentioned in the source code where the overflows occur. System administrators should implement strict package repository validation and monitoring to prevent exploitation attempts. The vulnerabilities align with CWE-121 heap-based buffer overflow classifications and may map to ATT&CK techniques involving privilege escalation and code execution through software exploitation. Organizations should also consider implementing memory protection mechanisms such as stack canaries, address space layout randomization, and heap integrity checks to reduce the effectiveness of potential exploitation attempts while awaiting permanent patches.