CVE-2011-1398

Status: ModifiedMedium (4.3)—Exploit

Severity4.3Medium · CVSS 2.0

Exploitation probability10 %higher than 96% of CVEs

Active exploitationNonot in the CISA catalog

Public exploitAvailablePublished on Exploit-DB

The sapi_header_op function in main/SAPI.c in PHP before 5.3.11 and 5.4.x before 5.4.0RC2 does not check for %0D sequences (aka carriage return characters), which allows remote attackers to bypass an HTTP response-splitting protection mechanism via a crafted URL, related to improper interaction between the PHP header function and certain browsers, as demonstrated by Internet Explorer and Google Chrome.

CVSS

Base score: 4.3
Version: 2.0
Vector: AV:N/AC:M/Au:N/C:N/I:P/A:N

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 10 %
Percentile among all scored CVEs: 96
Score date: 10/21/2026

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).

Public exploits

Exploit code or detection templates are publicly available. This is not the same as confirmed active exploitation (KEV), but it raises the risk: patch with priority.

Published on Exploit-DB · PHP 5.3.11/5.4.0RC2 - 'header()' HTTP Header Injection (10/6/2011)

Affected technologies (1)

PHP — PHP

CWEs

CWE-20

References

Show 20 references

Raw JSON (NVD)

Show

{
  "id": "CVE-2011-1398",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 4.3,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:M/Au:N/C:N/I:P/A:N",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 8.6,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2012-08-30T22:55:02.497",
  "references": [
    {
      "url": "http://article.gmane.org/gmane.comp.php.devel/70584",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://lists.opensuse.org/opensuse-security-announce/2013-08/msg00006.html",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://openwall.com/lists/oss-security/2012/08/29/5",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://openwall.com/lists/oss-security/2012/09/05/15",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://rhn.redhat.com/errata/RHSA-2013-1307.html",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://secunia.com/advisories/55078",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://security-tracker.debian.org/tracker/CVE-2011-1398",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://www.securitytracker.com/id?1027463",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://www.ubuntu.com/usn/USN-1569-1",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://bugs.php.net/bug.php?id=60227",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://article.gmane.org/gmane.comp.php.devel/70584",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://lists.opensuse.org/opensuse-security-announce/2013-08/msg00006.html",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://openwall.com/lists/oss-security/2012/08/29/5",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://openwall.com/lists/oss-security/2012/09/05/15",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://rhn.redhat.com/errata/RHSA-2013-1307.html",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://secunia.com/advisories/55078",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://security-tracker.debian.org/tracker/CVE-2011-1398",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://www.securitytracker.com/id?1027463",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://www.ubuntu.com/usn/USN-1569-1",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://bugs.php.net/bug.php?id=60227",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "The sapi_header_op function in main/SAPI.c in PHP before 5.3.11 and 5.4.x before 5.4.0RC2 does not check for %0D sequences (aka carriage return characters), which allows remote attackers to bypass an HTTP response-splitting protection mechanism via a crafted URL, related to improper interaction between the PHP header function and certain browsers, as demonstrated by Internet Explorer and Google Chrome."
    },
    {
      "lang": "es",
      "value": "La función sapi_header_op en el archivo main/SAPI.c en PHP anterior a versión 5.3.11 y versiones 5.4.x anteriores a 5.4.0RC2, no comprueba si hay secuencias de %0D (también se conoce como caracteres de retorno de acarreo), lo que permite a atacantes remotos omitir un mecanismo de protección de división de respuesta HTTP por medio de una URL diseñada, relacionada con la interacción inapropiada entre la función de PHP header y ciertos navegadores, como es demostrado por Internet Explorer y Google Chrome."
    }
  ],
  "lastModified": "2026-06-16T23:29:16.327",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:php:php:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "967EAC47-405C-4AA9-AC96-D3D750029AD0",
              "versionEndIncluding": "5.3.10"
            },
            {
              "criteria": "cpe:2.3:a:php:php:5.3.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "9EF4B938-BB14-4C06-BEE9-10CA755C5DEF"
            },
            {
              "criteria": "cpe:2.3:a:php:php:5.3.1:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "981C922C-7A7D-473E-8C43-03AB62FB5B8B"
            },
            {
              "criteria": "cpe:2.3:a:php:php:5.3.2:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "5D0CD11A-09C2-4C60-8F0C-68E55BD6EE63"
            },
            {
              "criteria": "cpe:2.3:a:php:php:5.3.3:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "B0F40E4A-E125-4099-A8B3-D42614AA9312"
            },
            {
              "criteria": "cpe:2.3:a:php:php:5.3.4:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4933D9DD-A630-4A3D-9D13-9E182F5F6F8C"
            },
            {
              "criteria": "cpe:2.3:a:php:php:5.3.5:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A9E6D530-91FC-42F4-A427-6601238E0187"
            },
            {
              "criteria": "cpe:2.3:a:php:php:5.3.6:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "9EC938DB-E066-407F-BDF8-61A1C41136F7"
            },
            {
              "criteria": "cpe:2.3:a:php:php:5.3.7:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "ACDF768D-7F5A-4042-B7DD-398F65F3F094"
            },
            {
              "criteria": "cpe:2.3:a:php:php:5.3.8:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "2AF35BB6-C6B1-4683-A8BE-AA72CC34F5B5"
            },
            {
              "criteria": "cpe:2.3:a:php:php:5.3.9:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "EC3F1891-032D-409C-904C-A415D2323DFC"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}