CVE-2021-3489 Linux kernel eBPF RINGBUF map oversized allocation

2021-05-1100:00:00

CWE-787

CWE-119

canonical

www.cve.org

7.8 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

8.4 High

AI Score

Confidence

High

0.0005 Low

EPSS

Percentile

17.9%

JSON

The eBPF RINGBUF bpf_ringbuf_reserve() function in the Linux kernel did not check that the allocated size was smaller than the ringbuf size, allowing an attacker to perform out-of-bounds writes within the kernel and therefore, arbitrary code execution. This issue was fixed via commit 4b81ccebaeee (“bpf, ringbuf: Deny reserve of buffers larger than ringbuf”) (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced via 457f44363a88 (“bpf: Implement BPF ring buffer and verifier support for it”) (v5.8-rc1).

CNA Affected

[
  {
    "product": "Linux kernel",
    "vendor": "Linux",
    "versions": [
      {
        "lessThan": "v5.13-rc4",
        "status": "affected",
        "version": "trunk",
        "versionType": "custom"
      },
      {
        "lessThan": "v5.12.4",
        "status": "affected",
        "version": "linux-5.12.y",
        "versionType": "custom"
      },
      {
        "lessThan": "v5.11.21",
        "status": "affected",
        "version": "linux-5.11.y",
        "versionType": "custom"
      },
      {
        "lessThan": "v5.10.37",
        "status": "affected",
        "version": "linux-5.10.y",
        "versionType": "custom"
      },
      {
        "lessThan": "5.8*",
        "status": "affected",
        "version": "v5.8",
        "versionType": "custom"
      }
    ]
  }
]