Full Report
CISA confirmed on Thursday that a high-severity privilege escalation flaw in the Linux kernel is now being exploited in ransomware attacks. [...]
Analysis Summary
# Vulnerability: Linux Kernel nf_tables Use-After-Free Leading to Privilege Escalation
## CVE Details
- CVE ID: CVE-2024-1086
- CVSS Score: Not explicitly provided, but described as **High-severity**
- CWE: Use-After-Free (Implied by description)
## Affected Systems
- Products: Linux Kernel
- Versions: Kernel versions between **3.15** and **6.8-rc1**. Specific mention of exploitation targeting versions between **5.14** and **6.6**.
- Configurations: Systems using the `netfilter: nf_tables` component. Affects major distributions including Debian, Ubuntu, Fedora, and Red Hat.
## Vulnerability Description
The vulnerability is a **use-after-free (UAF) weakness** located within the **`netfilter: nf_tables` kernel component**. Successful exploitation allows a local attacker to gain elevated privileges, potentially achieving **root-level access** on the compromised system through local privilege escalation. The flaw was introduced in a commit in February 2014 and was fixed via a commit submitted in January 2024.
## Exploitation
- Status: **Exploited in the wild** (Confirmed by CISA in ransomware campaigns).
- Complexity: **Low** (PoC demonstrated achieving LPE).
- Attack Vector: **Local** (Requires local access to escalate privileges).
## Impact
- Confidentiality: **High** (Root access allows file modification/theft).
- Integrity: **High** (Root access allows disabling defenses, modifying system files, installing malware).
- Availability: **High** (System takeover implies potential service disruption).
## Remediation
### Patches
- The vulnerability was fixed via a commit submitted in January 2024 (`f342de4e2f33e0e39165d8639387aa6c19dff660`). Users should update their Linux kernels to versions incorporating this fix (typically kernel versions newer than 6.8-rc1 or patched versions of older branches).
### Workarounds
1. **Blocklist 'nf_tables'** if the component is not actively needed or used.
2. **Restrict access to user namespaces** to limit the potential attack surface.
3. Load the **Linux Kernel Runtime Guard (LKRG)** module (Note: This may cause system instability).
## Detection
- Indicators of Compromise: Successful exploitation leads to unknown processes running with root privileges or unauthorized system modifications.
- Detection methods and tools: CISA added this to its KEV catalog; organizations should prioritize patching for all systems listed in vendor advisories referencing CVE-2024-1086.
## References
- Vendor advisories: CISA Known Exploited Vulnerabilities Catalog (KEV) entry for CVE-2024-1086.
- Relevant links - defanged:
- Initial disclosure documentation (commit in Jan 2024): hxxps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f342de4e2f33e0e39165d8639387aa6c19dff660
- PoC availability: hxxp://github.com/Notselwyn/CVE-2024-1086