CVE-2026-90018

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix OOB read / stack overflow in rtw_get_wps_attr() rtw_get_wps_attr() walks WPS attributes inside a WPS IE taken from a wireless management frame. For each candidate attribute it only checks that the fixed 4-byte attribute header (2-byte ID + 2-byte length) fits inside the IE: if (attr_ptr + 4 > wps_ie + wps_ielen) break; u16 attr_id = get_unaligned_be16(attr_ptr); u16 attr_data_len = get_unaligned_be16(attr_ptr + 2); u16 attr_len = attr_data_len + 4; attr_data_len (and therefore attr_len) is read directly from the wire and is never checked against the remaining bytes in the IE before being used as the size of: memcpy(buf_attr, attr_ptr, attr_len); Since attr_len is fully attacker controlled (0 to 65535+4), this is both a heap OOB read of wps_ie, and, more seriously, a stack buffer overflow at several call sites where buf_attr is a single-byte stack variable, e.g. rtw_get_wps_attr_content()'s callers passing WPS_ATTR_SELECTED_REGISTRAR into a stack "u8 sr"/"u8 selected_registrar" (drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c, drivers/staging/rtl8723bs/core/rtw_mlme_ext.c). A crafted WPS IE in a beacon or probe response processed during scanning can therefore smash the stack of the parsing thread. rtw_get_wps_attr_content() itself has no independent length check and simply trusts the attr_len it gets back from rtw_get_wps_attr(), so fixing the bound here also fixes that caller. The "attr_ptr + 4 > wps_ie + wps_ielen" header check above was added by commit 1463ca3ec6601 ("staging: rtl8723bs: fix OOB reads in rtw_get_sec_ie(), rtw_get_wapi_ie(), and rtw_get_wps_attr()"), which bounded the fixed header but never extended the check to cover the variable-length attribute data that follows it. Add that missing check before attr_len is used as a memcpy() length or accepted as a match.

Severity

HIGH

CVSS score

8.8 (v3.1)

Vulnerability status

Received

Source identifier

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

Published

2026-09-16 11:17:14.647000

Last modified

2026-10-19 09:18:49.780000

View original CVE JSON

{
  "id": "CVE-2026-90018",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-16T11:17:14.647",
  "lastModified": "2026-10-19T09:18:49.780",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nstaging: rtl8723bs: fix OOB read / stack overflow in rtw_get_wps_attr()\n\nrtw_get_wps_attr() walks WPS attributes inside a WPS IE taken from\na wireless management frame. For each candidate attribute it only\nchecks that the fixed 4-byte attribute header (2-byte ID + 2-byte\nlength) fits inside the IE:\n\n\tif (attr_ptr + 4 > wps_ie + wps_ielen)\n\t\tbreak;\n\tu16 attr_id = get_unaligned_be16(attr_ptr);\n\tu16 attr_data_len = get_unaligned_be16(attr_ptr + 2);\n\tu16 attr_len = attr_data_len + 4;\n\nattr_data_len (and therefore attr_len) is read directly from the\nwire and is never checked against the remaining bytes in the IE\nbefore being used as the size of:\n\n\tmemcpy(buf_attr, attr_ptr, attr_len);\n\nSince attr_len is fully attacker controlled (0 to 65535+4), this is\nboth a heap OOB read of wps_ie, and, more seriously, a stack buffer\noverflow at several call sites where buf_attr is a single-byte\nstack variable, e.g. rtw_get_wps_attr_content()'s callers passing\nWPS_ATTR_SELECTED_REGISTRAR into a stack \"u8 sr\"/\"u8\nselected_registrar\" (drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c,\ndrivers/staging/rtl8723bs/core/rtw_mlme_ext.c). A crafted WPS IE in a\nbeacon or probe response processed during scanning can therefore\nsmash the stack of the parsing thread.\n\nrtw_get_wps_attr_content() itself has no independent length check\nand simply trusts the attr_len it gets back from rtw_get_wps_attr(),\nso fixing the bound here also fixes that caller.\n\nThe \"attr_ptr + 4 > wps_ie + wps_ielen\" header check above was added\nby commit 1463ca3ec6601 (\"staging: rtl8723bs: fix OOB reads in\nrtw_get_sec_ie(), rtw_get_wapi_ie(), and rtw_get_wps_attr()\"), which\nbounded the fixed header but never extended the check to cover the\nvariable-length attribute data that follows it. Add that missing\ncheck before attr_len is used as a memcpy() length or accepted as a\nmatch."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/staging/rtl8723bs/core/rtw_ieee80211.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "lessThan": "931640dfcb8cfa08f6cfb46229716d8072356420",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "lessThan": "3a6457ebf39080b87c712657fdb38f34a24fc3ff",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "lessThan": "fd5e24ea8373347d0352f153a66e8647337d1b10",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "lessThan": "a53d1ac9ce63db07943b2b2248111003851fb00f",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "lessThan": "ff61aa3289355dafa811550a1764691cd1f5d33b",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "lessThan": "34f51d196c43a42046d229de5e79025d5ca553ca",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "lessThan": "99aa998dec83ba180822f70e6d48a514fc81c20d",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/staging/rtl8723bs/core/rtw_ieee80211.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.12",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.12",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.221",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.188",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.157",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.110",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.51",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.5",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "attackVector": "ADJACENT_NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/34f51d196c43a42046d229de5e79025d5ca553ca",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3a6457ebf39080b87c712657fdb38f34a24fc3ff",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/931640dfcb8cfa08f6cfb46229716d8072356420",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/99aa998dec83ba180822f70e6d48a514fc81c20d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a53d1ac9ce63db07943b2b2248111003851fb00f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/fd5e24ea8373347d0352f153a66e8647337d1b10",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ff61aa3289355dafa811550a1764691cd1f5d33b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}