A vulnerability classified as critical was found in Linux Kernel up to 4.14.x/4.15.x/4.16.x/4.17.x/4.18.12 (Operating System). This vulnerability affects the function adjust_scalar_min_max_vals of the file kernel/bpf/verifier.c of the component BPF Verifier. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel 4.14.x, 4.15.x, 4.16.x, 4.17.x, and 4.18.x before 4.18.13, faulty computation of numeric bounds in the BPF verifier permits out-of-bounds memory accesses because adjust_scalar_min_max_vals in kernel/bpf/verifier.c mishandles 32-bit right shifts.

The bug was discovered 10/03/2018. The weakness was published 10/17/2018 (Website). The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2018-18445 since 10/17/2018. The attack needs to be approached locally. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available.

The vulnerability was handled as a non-public zero-day exploit for at least 14 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 119302 (Ubuntu 18.10 : linux-aws vulnerabilities (USN-3832-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Ubuntu Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 171731 (SUSE Enterprise Linux Security Update for the Linux Kernel (SUSE-SU-2018:3934-1)).

Upgrading to version 4.18.13 eliminates this vulnerability. A possible mitigation has been published 2 months after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (119302). Similar entries are available at 114359, 124773, 125976 and 126010.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17
• 4.18.0
• 4.18.1
• 4.18.2
• 4.18.3
• 4.18.4
• 4.18.5
• 4.18.6
• 4.18.7
• 4.18.8
• 4.18.9
• 4.18.10
• 4.18.11
• 4.18.12

License

• open-source

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CPE 2.2info

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