FKIE_CVE-2026-74649

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-10-14 13:10
Severity
8.8 (High) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix missing shared-key auth challenge length check The WEP shared-key authentication handler uses the challenge-text element's attacker-controlled length without checking it against the fixed 128-byte chg_txt buffer. In OnAuthClient() the length from rtw_get_ie() - up to 255 - is used to perform memcpy() into the 128-byte pmlmeinfo->chg_txt, so a malicious AP sending a malformed WLAN_EID_CHALLENGE element can overflow/underfill chg_txt by up to 127 bytes. It is reachable over the air, before association, during shared-key authentication. In the case of an overflow, the driver can write out of bounds. In the case of an underfill, the driver can echo stale buffer memory. The challenge text is defined to be exactly 128 octets, which is already provided as the WLAN_AUTH_CHALLENGE_LEN define; require the element to be exactly that length before use.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2c56ef658ac8c6bca36bc5574715e8f717207c6c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/39ae1033071001af9bb4573ebdbb43bbbe88f749
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4ba402fd47009d20e51dbfc934abb562098ea35b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4d018e7d7d908bdfcb5ecfa922b1d5cb9ddb3722
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6235b5156b48ed5d1ce3410d8f0b2fd67d30d944
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/87c2f073d2aaea041d531b8e579c47570b54b3b7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a28a4b0592e4a37ea471bc0d308513a93133ce7e
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/staging/rtl8723bs/core/rtw_mlme_ext.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "39ae1033071001af9bb4573ebdbb43bbbe88f749",
              "status": "affected",
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "versionType": "git"
            },
            {
              "lessThan": "4d018e7d7d908bdfcb5ecfa922b1d5cb9ddb3722",
              "status": "affected",
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "versionType": "git"
            },
            {
              "lessThan": "4ba402fd47009d20e51dbfc934abb562098ea35b",
              "status": "affected",
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "versionType": "git"
            },
            {
              "lessThan": "87c2f073d2aaea041d531b8e579c47570b54b3b7",
              "status": "affected",
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "versionType": "git"
            },
            {
              "lessThan": "a28a4b0592e4a37ea471bc0d308513a93133ce7e",
              "status": "affected",
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "versionType": "git"
            },
            {
              "lessThan": "6235b5156b48ed5d1ce3410d8f0b2fd67d30d944",
              "status": "affected",
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "versionType": "git"
            },
            {
              "lessThan": "2c56ef658ac8c6bca36bc5574715e8f717207c6c",
              "status": "affected",
              "version": "554c0a3abf216c991c5ebddcdb2c08689ecd290b",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/staging/rtl8723bs/core/rtw_mlme_ext.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.12"
            },
            {
              "lessThan": "4.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.152",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nstaging: rtl8723bs: fix missing shared-key auth challenge length check\n\nThe WEP shared-key authentication handler uses the challenge-text\nelement\u0027s attacker-controlled length without checking it against the\nfixed 128-byte chg_txt buffer.\n\nIn OnAuthClient() the length from rtw_get_ie() - up to 255 - is used\nto perform memcpy() into the 128-byte pmlmeinfo-\u003echg_txt, so a\nmalicious AP sending a malformed WLAN_EID_CHALLENGE element can\noverflow/underfill chg_txt by up to 127 bytes. It is reachable over the\nair, before association, during shared-key authentication. In the case\nof an overflow, the driver can write out of bounds. In the case of an\nunderfill, the driver can echo stale buffer memory.\n\nThe challenge text is defined to be exactly 128 octets, which is\nalready provided as the WLAN_AUTH_CHALLENGE_LEN define; require the\nelement to be exactly that length before use."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nstaging: rtl8723bs: corregir la falta de comprobaci\u00f3n de longitud del desaf\u00edo de autenticaci\u00f3n de clave compartida\n\nEl gestor de autenticaci\u00f3n de clave compartida WEP utiliza la longitud controlada por el atacante del elemento de texto de desaf\u00edo sin comprobarla contra el b\u00fafer fijo chg_txt de 128 bytes.\n\nEn OnAuthClient() se utiliza la longitud de rtw_get_ie() - hasta 255 - para realizar memcpy() en pmlmeinfo -\u003e chg_txt de 128 bytes, por lo que un AP malicioso que env\u00ede un elemento WLAN_EID_CHALLENGE malformado puede desbordar/subdesbordar chg_txt hasta en 127 bytes. Es alcanzable por aire, antes de la asociaci\u00f3n, durante la autenticaci\u00f3n de clave compartida. En el caso de un desbordamiento, el controlador puede escribir fuera de los l\u00edmites. En el caso de un subdesbordamiento, el controlador puede hacer eco de memoria de b\u00fafer obsoleta.\n\nEl texto de desaf\u00edo est\u00e1 definido para ser exactamente 128 octetos, lo cual ya se proporciona como la definici\u00f3n WLAN_AUTH_CHALLENGE_LEN; se requiere que el elemento tenga exactamente esa longitud antes de su uso."
    }
  ],
  "id": "CVE-2026-74649",
  "lastModified": "2026-10-14T13:10:00.187",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-22T16:16:38.290",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2c56ef658ac8c6bca36bc5574715e8f717207c6c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/39ae1033071001af9bb4573ebdbb43bbbe88f749"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4ba402fd47009d20e51dbfc934abb562098ea35b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4d018e7d7d908bdfcb5ecfa922b1d5cb9ddb3722"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6235b5156b48ed5d1ce3410d8f0b2fd67d30d944"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/87c2f073d2aaea041d531b8e579c47570b54b3b7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a28a4b0592e4a37ea471bc0d308513a93133ce7e"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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