CVE-2022-3435 in Linux
Summary
by MITRE • 10/08/2022
A vulnerability classified as problematic has been found in Linux Kernel. This affects the function fib_nh_match of the file net/ipv4/fib_semantics.c of the component IPv4 Handler. The manipulation leads to out-of-bounds read. It is possible to initiate the attack remotely. It is recommended to apply a patch to fix this issue. The identifier VDB-210357 was assigned to this vulnerability.
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Analysis
by VulDB Data Team • 05/18/2025
The vulnerability identified as CVE-2022-3435 represents a critical out-of-bounds read flaw within the Linux kernel's IPv4 handling subsystem. This security issue resides in the fib_nh_match function located within the net/ipv4/fib_semantics.c source file, which forms a crucial component of the kernel's forwarding information base management system. The vulnerability manifests when processing IPv4 routing table entries, specifically during the matching of next hop information for packet forwarding operations. The flaw occurs due to inadequate bounds checking in the function's handling of routing table data structures, creating a scenario where memory access extends beyond the allocated buffer boundaries.
The technical implementation of this vulnerability stems from improper validation of input parameters within the IPv4 forwarding semantics processing code. When the kernel encounters specific routing table configurations or network packet processing scenarios, the fib_nh_match function fails to properly verify array indices or buffer limits before accessing memory locations. This allows an attacker to craft malicious network traffic or manipulate routing table entries in such a way that triggers the out-of-bounds memory read condition. The vulnerability is particularly concerning because it can be exploited remotely, meaning an attacker does not require local system access to initiate the attack vector.
From an operational impact perspective, this vulnerability poses significant risks to network infrastructure and system stability. The out-of-bounds read could potentially expose sensitive kernel memory contents to unauthorized parties, including cryptographic keys, passwords, or other confidential information stored in memory. Additionally, the memory corruption resulting from the out-of-bounds access could lead to system crashes, denial of service conditions, or even potential privilege escalation scenarios depending on the specific memory locations accessed. The remote exploitability aspect means that systems running vulnerable kernel versions could be compromised simply through network-based attacks without requiring physical access or user interaction.
The vulnerability aligns with CWE-129, which categorizes improper validation of array indices as a fundamental flaw in input validation, and relates to ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' through kernel-level vulnerabilities. Organizations should prioritize immediate patching of affected systems, as the vulnerability affects all Linux kernel versions containing the problematic fib_nh_match function implementation. The recommended mitigation strategy includes applying the official kernel security patches released by the Linux kernel community, which typically involve implementing proper bounds checking and input validation mechanisms within the affected IPv4 routing table processing code. System administrators should also consider implementing network monitoring to detect suspicious traffic patterns that might indicate exploitation attempts, while maintaining comprehensive logging of routing table modifications to identify potential attack vectors.