CVE-2021-4156 (GCVE-0-2021-4156)

Vulnerability from cvelistv5 – Published: 2022-03-23 00:00 – Updated: 2025-12-11 12:06
VLAI
Summary
An out-of-bounds read flaw was found in libsndfile's FLAC codec functionality. An attacker who is able to submit a specially crafted file (via tricking a user to open or otherwise) to an application linked with libsndfile and using the FLAC codec, could trigger an out-of-bounds read that would most likely cause a crash but could potentially leak memory information that could be used in further exploitation of other flaws.
CWE
Assigner
redhat CNA under the redhat root
CNA scorecard B 82/100 over 1131 records in the last 180 days details
Impacted products
Vendor Product Version CPE status
n/a libsndfile Affected: libsndfile 1.1.0
Show details on NVD website

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-12-11T12:06:14.134Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2027690"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/libsndfile/libsndfile/pull/732/commits/4c30646abf7834e406f7e2429c70bc254e18beab"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/libsndfile/libsndfile/issues/731"
          },
          {
            "name": "[debian-lts-announce] 20220628 [SECURITY] [DLA 3058-1] libsndfile security update",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2022/06/msg00020.html"
          },
          {
            "name": "[debian-lts-announce] 20220929 [SECURITY] [DLA 3126-1] libsndfile security update",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2022/09/msg00036.html"
          },
          {
            "name": "GLSA-202309-11",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://security.gentoo.org/glsa/202309-11"
          },
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/12/msg00013.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "libsndfile",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "libsndfile 1.1.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "An out-of-bounds read flaw was found in libsndfile\u0027s FLAC codec functionality. An attacker who is able to submit a specially crafted file (via tricking a user to open or otherwise) to an application linked with libsndfile and using the FLAC codec, could trigger an out-of-bounds read that would most likely cause a crash but could potentially leak memory information that could be used in further exploitation of other flaws."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-125",
              "description": "CWE-125",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-09-29T12:06:18.959Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2027690"
        },
        {
          "url": "https://github.com/libsndfile/libsndfile/pull/732/commits/4c30646abf7834e406f7e2429c70bc254e18beab"
        },
        {
          "url": "https://github.com/libsndfile/libsndfile/issues/731"
        },
        {
          "name": "[debian-lts-announce] 20220628 [SECURITY] [DLA 3058-1] libsndfile security update",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2022/06/msg00020.html"
        },
        {
          "name": "[debian-lts-announce] 20220929 [SECURITY] [DLA 3126-1] libsndfile security update",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2022/09/msg00036.html"
        },
        {
          "name": "GLSA-202309-11",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://security.gentoo.org/glsa/202309-11"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2021-4156",
    "datePublished": "2022-03-23T00:00:00.000Z",
    "dateReserved": "2021-12-22T00:00:00.000Z",
    "dateUpdated": "2025-12-11T12:06:14.134Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-4156",
      "date": "2026-11-07",
      "epss": "0.01754",
      "percentile": "0.78052"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "libsndfile",
                "vendor": "n/a",
                "versions": [
                  {
                    "status": "affected",
                    "version": "libsndfile 1.1.0"
                  }
                ]
              }
            ],
            "source": "secalert@redhat.com"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:libsndfile_project:libsndfile:1.1.10:*:*:*:*:*:*:*",
                    "matchCriteriaId": "820C772A-84DE-406C-881A-3C3D116315F4",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "An out-of-bounds read flaw was found in libsndfile\u0027s FLAC codec functionality. An attacker who is able to submit a specially crafted file (via tricking a user to open or otherwise) to an application linked with libsndfile and using the FLAC codec, could trigger an out-of-bounds read that would most likely cause a crash but could potentially leak memory information that could be used in further exploitation of other flaws."
          },
          {
            "lang": "es",
            "value": "Se ha encontrado un fallo de lectura fuera de l\u00edmites en la funcionalidad del c\u00f3dec FLAC de libsndfile. Un atacante que sea capaz de enviar un archivo especialmente dise\u00f1ado (por medio de enga\u00f1ar a un usuario para que lo abra o de otro modo) a una aplicaci\u00f3n enlazada con libsndfile y que use el c\u00f3dec FLAC, podr\u00eda desencadenar una lectura fuera de l\u00edmites que muy probablemente causar\u00eda un fallo, pero podr\u00eda filtrar informaci\u00f3n de la memoria que podr\u00eda usarse en una explotaci\u00f3n posterior de otros fallos"
          }
        ],
        "id": "CVE-2021-4156",
        "lastModified": "2026-06-17T04:19:07.763",
        "metrics": {
          "cvssMetricV2": [
            {
              "acInsufInfo": false,
              "baseSeverity": "MEDIUM",
              "cvssData": {
                "accessComplexity": "MEDIUM",
                "accessVector": "NETWORK",
                "authentication": "NONE",
                "availabilityImpact": "PARTIAL",
                "baseScore": 5.8,
                "confidentialityImpact": "PARTIAL",
                "integrityImpact": "NONE",
                "vectorString": "AV:N/AC:M/Au:N/C:P/I:N/A:P",
                "version": "2.0"
              },
              "exploitabilityScore": 8.6,
              "impactScore": 4.9,
              "obtainAllPrivilege": false,
              "obtainOtherPrivilege": false,
              "obtainUserPrivilege": false,
              "source": "nvd@nist.gov",
              "type": "Primary",
              "userInteractionRequired": true
            }
          ],
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 7.1,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "LOW",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 2.8,
              "impactScore": 4.2,
              "source": "nvd@nist.gov",
              "type": "Primary"
            }
          ]
        },
        "published": "2022-03-23T20:15:10.097",
        "references": [
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Exploit",
              "Issue Tracking",
              "Third Party Advisory"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2027690"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Exploit",
              "Issue Tracking",
              "Third Party Advisory"
            ],
            "url": "https://github.com/libsndfile/libsndfile/issues/731"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://github.com/libsndfile/libsndfile/pull/732/commits/4c30646abf7834e406f7e2429c70bc254e18beab"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2022/06/msg00020.html"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2022/09/msg00036.html"
          },
          {
            "source": "secalert@redhat.com",
            "url": "https://security.gentoo.org/glsa/202309-11"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Exploit",
              "Issue Tracking",
              "Third Party Advisory"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2027690"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Exploit",
              "Issue Tracking",
              "Third Party Advisory"
            ],
            "url": "https://github.com/libsndfile/libsndfile/issues/731"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://github.com/libsndfile/libsndfile/pull/732/commits/4c30646abf7834e406f7e2429c70bc254e18beab"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2022/06/msg00020.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2022/09/msg00036.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://lists.debian.org/debian-lts-announce/2025/12/msg00013.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://security.gentoo.org/glsa/202309-11"
          }
        ],
        "sourceIdentifier": "secalert@redhat.com",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-125"
              }
            ],
            "source": "secalert@redhat.com",
            "type": "Secondary"
          },
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-125"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-11-07T13:33:04+00:00",
      "cve": "CVE-2021-4156",
      "id": "CVE-2021-4156",
      "initial_release_date": "2021-04-13T00:00:00+00:00",
      "product_status:fixed": "41",
      "product_status:known_affected": "7",
      "product_status:known_not_affected": "4",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "libsndfile: heap out-of-bounds read in src/flac.c in flac_buffer_copy",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-4156.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON
How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Events included in the timeline

Loading timeline…


    Loading…

    Loading…

    Loading…

    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.