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CVE-2022-20952

Status: ModifiedMedium (5.3)—

A vulnerability in the scanning engines of Cisco AsyncOS Software for Cisco Secure Web Appliance, formerly known as Cisco Web Security Appliance (WSA), could allow an unauthenticated, remote attacker to bypass a configured rule, thereby allowing traffic onto a network that should have been blocked.

This vulnerability exists because malformed, encoded traffic is not properly detected. An attacker could exploit this vulnerability by connecting through an affected device to a malicious server and receiving malformed HTTP responses. A successful exploit could allow the attacker to bypass an explicit block rule and receive traffic that should have been rejected by the device.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

Cisco — Asyncos

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2022-20952",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "psirt@cisco.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.3,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 3.9
      },
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.3,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "psirt@cisco.com",
      "affectedData": [
        {
          "vendor": "Cisco",
          "product": "Cisco Secure Web Appliance",
          "versions": [
            {
              "status": "affected",
              "version": "11.8.0-414"
            },
            {
              "status": "affected",
              "version": "11.8.1-023"
            },
            {
              "status": "affected",
              "version": "11.8.3-018"
            },
            {
              "status": "affected",
              "version": "11.8.3-021"
            },
            {
              "status": "affected",
              "version": "12.0.1-268"
            },
            {
              "status": "affected",
              "version": "12.0.3-007"
            },
            {
              "status": "affected",
              "version": "12.5.2-007"
            },
            {
              "status": "affected",
              "version": "12.5.1-011"
            },
            {
              "status": "affected",
              "version": "12.5.4-005"
            },
            {
              "status": "affected",
              "version": "12.5.5-004"
            },
            {
              "status": "affected",
              "version": "14.5.0-498"
            },
            {
              "status": "affected",
              "version": "14.0.3-014"
            },
            {
              "status": "affected",
              "version": "14.0.2-012"
            }
          ]
        }
      ]
    }
  ],
  "published": "2023-03-01T08:15:10.270",
  "references": [
    {
      "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wsa-bypass-bwBfugek",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "psirt@cisco.com"
    },
    {
      "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wsa-bypass-bwBfugek",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "psirt@cisco.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        }
      ]
    },
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A vulnerability in the scanning engines of Cisco AsyncOS Software for Cisco Secure Web Appliance, formerly known as Cisco Web Security Appliance (WSA), could allow an unauthenticated, remote attacker to bypass a configured rule, thereby allowing traffic onto a network that should have been blocked.\r\n\r This vulnerability exists because malformed, encoded traffic is not properly detected. An attacker could exploit this vulnerability by connecting through an affected device to a malicious server and receiving malformed HTTP responses. A successful exploit could allow the attacker to bypass an explicit block rule and receive traffic that should have been rejected by the device."
    }
  ],
  "lastModified": "2026-06-17T04:25:31.107",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:cisco:asyncos:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F123F722-4765-49AE-AFE7-C889F3658C57",
              "versionEndExcluding": "14.0.4",
              "versionStartIncluding": "11.8"
            },
            {
              "criteria": "cpe:2.3:o:cisco:asyncos:14.5.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "23EC2FAD-D9BF-450F-989E-ED862E263F4E"
            }
          ],
          "operator": "OR"
        },
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:h:cisco:s195:-:*:*:*:*:*:*:*",
              "vulnerable": false,
              "matchCriteriaId": "9797CD28-48A3-45BD-BF68-F0DF6F5A5579"
            },
            {
              "criteria": "cpe:2.3:h:cisco:s395:-:*:*:*:*:*:*:*",
              "vulnerable": false,
              "matchCriteriaId": "C6D20279-8176-449A-AF4C-E2C90F370B30"
            },
            {
              "criteria": "cpe:2.3:h:cisco:s695:-:*:*:*:*:*:*:*",
              "vulnerable": false,
              "matchCriteriaId": "D9408ADA-7A8F-4528-8236-65713CF642D5"
            }
          ],
          "operator": "OR"
        }
      ],
      "operator": "AND"
    }
  ],
  "sourceIdentifier": "psirt@cisco.com"
}