Vulnerability-Lookup

FKIE_CVE-2021-26910

Vulnerability from fkie_nvd - Published: 2021-02-08 20:15 - Updated: 2026-06-17 03:43

Severity

7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.0 (High) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Summary

Firejail before 0.9.64.4 allows attackers to bypass intended access restrictions because there is a TOCTOU race condition between a stat operation and an OverlayFS mount operation.

References

URL	Tags
cve@mitre.org	http://www.openwall.com/lists/oss-security/2021/02/09/1	Exploit, Mailing List, Patch, Third Party Advisory
cve@mitre.org	https://github.com/netblue30/firejail/commit/97d8a03cad19501f017587cc4e47d8418273834b	Patch, Third Party Advisory
cve@mitre.org	https://github.com/netblue30/firejail/releases/tag/0.9.64.4	Release Notes, Third Party Advisory
cve@mitre.org	https://lists.debian.org/debian-lts-announce/2021/02/msg00015.html	Third Party Advisory
cve@mitre.org	https://security.gentoo.org/glsa/202105-19	Third Party Advisory
cve@mitre.org	https://unparalleled.eu/blog/2021/20210208-rigged-race-against-firejail-for-local-root/	Exploit, Third Party Advisory
cve@mitre.org	https://unparalleled.eu/publications/2021/advisory-unpar-2021-0.txt	Exploit, Third Party Advisory
cve@mitre.org	https://www.debian.org/security/2021/dsa-4849	Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	http://www.openwall.com/lists/oss-security/2021/02/09/1	Exploit, Mailing List, Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/netblue30/firejail/commit/97d8a03cad19501f017587cc4e47d8418273834b	Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/netblue30/firejail/releases/tag/0.9.64.4	Release Notes, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://lists.debian.org/debian-lts-announce/2021/02/msg00015.html	Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://security.gentoo.org/glsa/202105-19	Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://unparalleled.eu/blog/2021/20210208-rigged-race-against-firejail-for-local-root/	Exploit, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://unparalleled.eu/publications/2021/advisory-unpar-2021-0.txt	Exploit, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://www.debian.org/security/2021/dsa-4849	Third Party Advisory

Impacted products

Vendor	Product	Version
firejail_project	firejail	*
debian	debian_linux	9.0
debian	debian_linux	10.0

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "source": "cve@mitre.org"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:firejail_project:firejail:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "4457E838-C33E-4AEA-842B-8A155CC63213",
              "versionEndExcluding": "0.9.64.4",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
    {
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            {
              "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": "Firejail before 0.9.64.4 allows attackers to bypass intended access restrictions because there is a TOCTOU race condition between a stat operation and an OverlayFS mount operation."
    },
    {
      "lang": "es",
      "value": "Firejail versiones anteriores a 0.9.64.4, permite a atacantes omitir las restricciones de acceso previstas porque se presenta una condici\u00f3n de carrera TOCTOU entre una operaci\u00f3n de estad\u00edstica y una operaci\u00f3n de montaje OverlayFS"
    }
  ],
  "id": "CVE-2021-26910",
  "lastModified": "2026-06-17T03:43:59.100",
  "metrics": {
    "cvssMetricV2": [
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        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "MEDIUM",
          "accessVector": "LOCAL",
          "authentication": "NONE",
          "availabilityImpact": "COMPLETE",
          "baseScore": 6.9,
          "confidentialityImpact": "COMPLETE",
          "integrityImpact": "COMPLETE",
          "vectorString": "AV:L/AC:M/Au:N/C:C/I:C/A:C",
          "version": "2.0"
        },
        "exploitabilityScore": 3.4,
        "impactScore": 10.0,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
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          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
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          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
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          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
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          "scope": "UNCHANGED",
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  "published": "2021-02-08T20:15:13.090",
  "references": [
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      "tags": [
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    {
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      "tags": [
        "Third Party Advisory"
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      "url": "https://security.gentoo.org/glsa/202105-19"
    },
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    },
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  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Modified",
  "weaknesses": [
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          "value": "CWE-367"
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  ]
}

CVE-2021-26910 (GCVE-0-2021-26910)

Vulnerability from cvelistv5 – Published: 2021-02-08 19:56 – Updated: 2024-08-03 20:33

Summary

Firejail before 0.9.64.4 allows attackers to bypass intended access restrictions because there is a TOCTOU race condition between a stat operation and an OverlayFS mount operation.

Severity

7.8 (High)


                        
                          CVSS:3.1/AC:L/AV:L/A:H/C:H/I:H/PR:L/S:U/UI:N

CWE

Assigner

mitre mitre root

References

8 references

URL	Tags
https://github.com/netblue30/firejail/commit/97d8…	x_refsource_MISC
https://unparalleled.eu/publications/2021/advisor…	x_refsource_MISC
https://unparalleled.eu/blog/2021/20210208-rigged…	x_refsource_MISC
https://github.com/netblue30/firejail/releases/ta…	x_refsource_MISC
http://www.openwall.com/lists/oss-security/2021/02/09/1	mailing-listx_refsource_MLIST
https://www.debian.org/security/2021/dsa-4849	vendor-advisoryx_refsource_DEBIAN
https://lists.debian.org/debian-lts-announce/2021…	mailing-listx_refsource_MLIST
https://security.gentoo.org/glsa/202105-19	vendor-advisoryx_refsource_GENTOO

Show details on NVD website

JSON

To clipboard

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  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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.