« Back to list

CVE-2015-2877

Status: ModifiedLow (3.3)—

Kernel Samepage Merging (KSM) in the Linux kernel 2.6.32 through 4.x does not prevent use of a write-timing side channel, which allows guest OS users to defeat the ASLR protection mechanism on other guest OS instances via a Cross-VM ASL INtrospection (CAIN) attack. NOTE: the vendor states "Basically if you care about this attack vector, disable deduplication." Share-until-written approaches for memory conservation among mutually untrusting tenants are inherently detectable for information disclosure, and can be classified as potentially misunderstood behaviors rather than vulnerabilities

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 (2)

Linux — Linux KernelRedhat — Enterprise Linux

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2015-2877",
  "cveTags": [
    {
      "tags": [
        "disputed"
      ],
      "sourceIdentifier": "cret@cert.org"
    }
  ],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 2.1,
          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:L/Au:N/C:P/I:N/A:N",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "LOW",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 3.9,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 3.3,
          "attackVector": "LOCAL",
          "baseSeverity": "LOW",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "cret@cert.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2017-03-03T11:59:00.147",
  "references": [
    {
      "url": "http://www.antoniobarresi.com/files/cain_advisory.txt",
      "tags": [
        "Technical Description",
        "Third Party Advisory"
      ],
      "source": "cret@cert.org"
    },
    {
      "url": "http://www.kb.cert.org/vuls/id/935424",
      "tags": [
        "Third Party Advisory",
        "US Government Resource"
      ],
      "source": "cret@cert.org"
    },
    {
      "url": "http://www.securityfocus.com/bid/76256",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ],
      "source": "cret@cert.org"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1252096",
      "tags": [
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "source": "cret@cert.org"
    },
    {
      "url": "https://www.kb.cert.org/vuls/id/BGAR-A2CNKG",
      "tags": [
        "Third Party Advisory",
        "US Government Resource"
      ],
      "source": "cret@cert.org"
    },
    {
      "url": "https://www.kb.cert.org/vuls/id/BLUU-9ZAHZH",
      "tags": [
        "Third Party Advisory",
        "US Government Resource"
      ],
      "source": "cret@cert.org"
    },
    {
      "url": "https://www.usenix.org/system/files/conference/woot15/woot15-paper-barresi.pdf",
      "tags": [
        "Technical Description",
        "Third Party Advisory"
      ],
      "source": "cret@cert.org"
    },
    {
      "url": "http://www.antoniobarresi.com/files/cain_advisory.txt",
      "tags": [
        "Technical Description",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://www.kb.cert.org/vuls/id/935424",
      "tags": [
        "Third Party Advisory",
        "US Government Resource"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://www.securityfocus.com/bid/76256",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1252096",
      "tags": [
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://www.kb.cert.org/vuls/id/BGAR-A2CNKG",
      "tags": [
        "Third Party Advisory",
        "US Government Resource"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://www.kb.cert.org/vuls/id/BLUU-9ZAHZH",
      "tags": [
        "Third Party Advisory",
        "US Government Resource"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://www.usenix.org/system/files/conference/woot15/woot15-paper-barresi.pdf",
      "tags": [
        "Technical Description",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-200"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Kernel Samepage Merging (KSM) in the Linux kernel 2.6.32 through 4.x does not prevent use of a write-timing side channel, which allows guest OS users to defeat the ASLR protection mechanism on other guest OS instances via a Cross-VM ASL INtrospection (CAIN) attack.  NOTE: the vendor states \"Basically if you care about this attack vector, disable deduplication.\" Share-until-written approaches for memory conservation among mutually untrusting tenants are inherently detectable for information disclosure, and can be classified as potentially misunderstood behaviors rather than vulnerabilities"
    },
    {
      "lang": "es",
      "value": "** DISPUTADA ** Kernel Samepage Merging (KSM) en el kernel de Linux 2.6.32 hasta la versión 4.x no previene el uso de un canal lateral de sincronización de escritura, lo que permite a usuarios invitados del SO derrotar el mecanismo de protección de ASLR en otras instancias invitadas del SO a través de un ataque Cross-VM ASL INtrospection (CAIN). NOTA: el vendedor afirma \"Básicamente si te preocupa este vector de ataque, inhabilita la deduplicación\". Enfoques de compartir hasta escritura para conservación de memoria entre inquilinos mutuamente desconfiados son inherentemente detectables para divulgación de información y pueden clasificarse como comportamientos potencialmente malinterpretados en lugar de vulnerabilidades."
    }
  ],
  "lastModified": "2026-06-17T00:24:54.560",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "85A3B15D-C690-40D1-A2CE-3E2E5035DA99",
              "versionEndIncluding": "4.20.15",
              "versionStartIncluding": "2.6.32"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:redhat:enterprise_linux:4.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "6172AF57-B26D-45F8-BE3A-F75ABDF28F49"
            },
            {
              "criteria": "cpe:2.3:o:redhat:enterprise_linux:5.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "1D8B549B-E57B-4DFE-8A13-CAB06B5356B3"
            },
            {
              "criteria": "cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "2F6AB192-9D7D-4A9A-8995-E53A9DE9EAFC"
            },
            {
              "criteria": "cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "142AD0DD-4CF3-4D74-9442-459CE3347E3A"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cret@cert.org"
}