CVE-2021-47245

2024-05-2115:15:13

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux kernel

netfilter

vulnerability

fix

tcp options

parser

synproxy

out of bounds

nvd

6.7 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

13.1%

JSON

In the Linux kernel, the following vulnerability has been resolved:

netfilter: synproxy: Fix out of bounds when parsing TCP options

The TCP option parser in synproxy (synproxy_parse_options) could read
one byte out of bounds. When the length is 1, the execution flow gets
into the loop, reads one byte of the opcode, and if the opcode is
neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds
the length of 1.

This fix is inspired by commit 9609dad263f8 (“ipv4: tcp_input: fix stack
out of bounds when parsing TCP options.”).

v2 changes:

Added an early return when length < 0 to avoid calling
skb_header_pointer with negative length.

Affected configurations

Vulners

Node

linuxlinux_kernelRange3.12–4.4.274

linuxlinux_kernelRange4.5.0–4.9.274

linuxlinux_kernelRange4.10.0–4.14.238

linuxlinux_kernelRange4.15.0–4.19.196

linuxlinux_kernelRange4.20.0–5.4.128

linuxlinux_kernelRange5.5.0–5.10.46

linuxlinux_kernelRange5.11.0–5.12.13

linuxlinux_kernelRange5.13.0≥

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/netfilter/nf_synproxy_core.c"
    ],
    "versions": [
      {
        "version": "48b1de4c110a",
        "lessThan": "e1eb98cfeafd",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "48b1de4c110a",
        "lessThan": "576c1526b4d8",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "48b1de4c110a",
        "lessThan": "674b5f0c6a4f",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "48b1de4c110a",
        "lessThan": "7d9a9a1a88a3",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "48b1de4c110a",
        "lessThan": "6defc77d48ef",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "48b1de4c110a",
        "lessThan": "9cdf299ba4e1",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "48b1de4c110a",
        "lessThan": "f648089337cb",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "48b1de4c110a",
        "lessThan": "5fc177ab7594",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/netfilter/nf_synproxy_core.c"
    ],
    "versions": [
      {
        "version": "3.12",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "3.12",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.4.274",
        "lessThanOrEqual": "4.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.9.274",
        "lessThanOrEqual": "4.9.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.14.238",
        "lessThanOrEqual": "4.14.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.196",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.128",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.46",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.13",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]