CVE-2023-53549
Description
An uncontrolled resource consumption flaw was found in the Linux kernel's netfilter ipset subsystem when processing large batch operations. A local user with CAP_NET_ADMIN capability can trigger this issue by adding or deleting a large number of ipset entries in a single operation, causing the kernel to execute long-running tasks without yielding. This results in soft lockup conditions and denial of service through system unresponsiveness.
Statement
The ipset code processes batch add/delete operations in a tight loop while holding the nfnl mutex. When users specify a large range of IP addresses or ports to add to or remove from a set, the kernel can spend extended periods (potentially seconds) without scheduling, leading to soft lockup detector warnings and system unresponsiveness. Previous attempts to limit the batch size were insufficient—the limits were still too high to prevent hung task conditions on slower systems. Exploitation requires CAP_NET_ADMIN capability, which is typically restricted to root or containers with explicit network administration privileges.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other); Reduce Performance
This issue can make the product perform more slowly. If an attacker can influence the number of iterations in the loop, then this performance problem might allow a denial of service by consuming more platform resources than intended.
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