FKIE_CVE-2026-48983

Vulnerability from fkie_nvd - Published: 2026-06-18 20:16 - Updated: 2026-06-22 17:56
Severity
5.8 (Medium) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L
Summary
pam_usb provides hardware authentication for Linux using ordinary removable media. In versions prior to 0.9.2, a symlink race condition exists in per-device and per-user pad directory creation. pam_usb uses a check-then-act pattern: it calls lstat() to test for existence and then calls mkdir() separately to create the directory. A local attacker can win the race between these calls by replacing the target path with a symlink to a directory they control. If successful, one-time pad files may be written to an attacker-controlled location, potentially exposing future pad values before use or disrupting authentication. This issue has been fixed in version 0.9.2.
References
security-advisories@github.comhttps://github.com/mcdope/pam_usb/releases/tag/0.9.2
security-advisories@github.comhttps://github.com/mcdope/pam_usb/security/advisories/GHSA-4j8q-67fq-3xc3
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "pam_usb",
          "vendor": "mcdope",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.9.2"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "pam_usb provides hardware authentication for Linux using ordinary removable media. In versions prior to 0.9.2, a symlink race condition exists in per-device and per-user pad directory creation. pam_usb uses a check-then-act pattern: it calls lstat() to test for existence and then calls mkdir() separately to create the directory. A local attacker can win the race between these calls by replacing the target path with a symlink to a directory they control. If successful, one-time pad files may be written to an attacker-controlled location, potentially exposing future pad values before use or disrupting authentication. This issue has been fixed in version 0.9.2."
    }
  ],
  "id": "CVE-2026-48983",
  "lastModified": "2026-06-22T17:56:35.757",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "LOCAL",
          "availabilityImpact": "LOW",
          "baseScore": 5.8,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 4.7,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-48983",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-06-22T12:41:19.864255Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-06-18T20:16:14.657",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/mcdope/pam_usb/releases/tag/0.9.2"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/mcdope/pam_usb/security/advisories/GHSA-4j8q-67fq-3xc3"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-367"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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