In the Linux kernel, the following vulnerability has been resolved: net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc As described in Gerrard's report [1], we have a UAF case when an hfsc class has a netem child qdisc. The crux of the issue is that hfsc is assuming that checking for cl->qdisc->q.qlen == 0 guarantees that it hasn't inserted the class in the vttree or eltree (which is not true for the netem duplicate case). This patch checks the n_active class variable to make sure that the code won't insert the class in the vttree or eltree twice, catering for the reentrant case. [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/
This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.8, requiring local system access to exploit with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 2 products from linux, from debian organizations running these solutions should prioritize assessment and patching.
Reported in 2025, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2025-05-16T13:15:52.437
2025-11-17T17:11:57.840
Analyzed
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSSv3.1: 7.8 (HIGH)
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Operating System | linux | linux_kernel | < 5.4.294 | Yes |
| Operating System | linux | linux_kernel | < 5.10.238 | Yes |
| Operating System | linux | linux_kernel | < 5.15.182 | Yes |
| Operating System | linux | linux_kernel | < 6.1.138 | Yes |
| Operating System | linux | linux_kernel | < 6.6.90 | Yes |
| Operating System | linux | linux_kernel | < 6.12.28 | Yes |
| Operating System | linux | linux_kernel | < 6.14.6 | Yes |
| Operating System | linux | linux_kernel | 5.0 | Yes |
| Operating System | linux | linux_kernel | 5.0 | Yes |
| Operating System | linux | linux_kernel | 5.0 | Yes |
| Operating System | linux | linux_kernel | 5.0 | Yes |
| Operating System | linux | linux_kernel | 5.0 | Yes |
| Operating System | linux | linux_kernel | 5.0 | Yes |
| Operating System | linux | linux_kernel | 5.0 | Yes |
| Operating System | linux | linux_kernel | 6.15 | Yes |
| Operating System | linux | linux_kernel | 6.15 | Yes |
| Operating System | linux | linux_kernel | 6.15 | Yes |
| Operating System | linux | linux_kernel | 6.15 | Yes |
| Operating System | debian | debian_linux | 11.0 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For linux's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.