Vulnerability-Lookup

GHSA-5453-GCX7-H56M

Vulnerability from github – Published: 2026-08-24 21:33 – Updated: 2026-08-24 21:33

Details

The exposed key is security-critical because it is used to sign Flask session cookies and is also involved in the legacy API-key key derivation. An attacker who obtains the key can generate valid session cookies and impersonate an authenticated user, including an administrator. In LDAP configurations, exploitation may be particularly straightforward because the session user loader does not require the supplied username to correspond to an existing local user.

Successful exploitation requires local access sufficient to read the improperly protected file, but can result in complete compromise of RansomLook's authentication and authorization controls.

The patch creates new secret-key files atomically with permissions 0600 and also restricts permissions on existing key files during application startup.

Severity

7.0 (High)


                  
                    CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-78553"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-276"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-24T20:17:24Z",
    "severity": "HIGH"
  },
  "details": "RansomLook created its Flask session-signing key without explicitly restricting the file permissions. The secret_key file was created using the process\u0027s default permissions and umask, resulting in permissions such as 0644 under a common 022 umask. Consequently, other local users able to access the RansomLook home directory could read the application\u0027s cryptographic secret.\n\n\nThe exposed key is security-critical because it is used to sign Flask session cookies and is also involved in the legacy API-key key derivation. An attacker who obtains the key can generate valid session cookies and impersonate an authenticated user, including an administrator. In LDAP configurations, exploitation may be particularly straightforward because the session user loader does not require the supplied username to correspond to an existing local user.\n\n\nSuccessful exploitation requires local access sufficient to read the improperly protected file, but can result in complete compromise of RansomLook\u0027s authentication and authorization controls.\n\n\nThe patch creates new secret-key files atomically with permissions 0600 and also restricts permissions on existing key files during application startup.",
  "id": "GHSA-5453-gcx7-h56m",
  "modified": "2026-08-24T21:33:45Z",
  "published": "2026-08-24T21:33:45Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-78553"
    },
    {
      "type": "WEB",
      "url": "https://github.com/RansomLook/RansomLook/commit/df9d47edcf02dd0125db869d5bc19d93f426d892"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-78553 (GCVE-0-2026-78553)

Vulnerability from cvelistv5 – Published: 2026-08-24 19:28 – Updated: 2026-08-24 20:07

Title

Insecure Flask Secret-Key File Permissions Allow Local Administrator Session Forgery in RansomLook

Summary

RansomLook created its Flask session-signing key without explicitly restricting the file permissions. The secret_key file was created using the process's default permissions and umask, resulting in permissions such as 0644 under a common 022 umask. Consequently, other local users able to access the RansomLook home directory could read the application's cryptographic secret. The exposed key is security-critical because it is used to sign Flask session cookies and is also involved in the legacy API-key key derivation. An attacker who obtains the key can generate valid session cookies and impersonate an authenticated user, including an administrator. In LDAP configurations, exploitation may be particularly straightforward because the session user loader does not require the supplied username to correspond to an existing local user. Successful exploitation requires local access sufficient to read the improperly protected file, but can result in complete compromise of RansomLook's authentication and authorization controls. The patch creates new secret-key files atomically with permissions 0600 and also restricts permissions on existing key files during application startup.

Severity

7 (High)


                        
                          CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-24 20:06 UTC

CWE

CWE-276 - Incorrect Default Permissions
CWE-732 - Incorrect Permission Assignment for Critical Resource

Assigner

CIRCL ENISA root

References

1 reference

URL	Tags
https://github.com/RansomLook/RansomLook/commit/d…	patch

Impacted products

1 product

Vendor	Product	Version
ransomlook	ransomlook	Affected: 0 , ≤ 2.0.0 (semver)

Credits

Jeroen Pinoy Fafner [_KeyZee_]

Show details on NVD website

JSON

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                "id": "CVE-2026-78553",
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                  },
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                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-24T20:06:47.525354Z",
                "version": "2.0.3"
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            }
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          "lang": "en",
          "type": "finder",
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        },
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          "type": "remediation developer",
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        }
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    "datePublished": "2026-08-24T19:28:49.323Z",
    "dateReserved": "2026-08-24T19:28:46.092Z",
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  },
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}

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.

Action not permitted

GHSA-5453-GCX7-H56M

CVE-2026-78553 (GCVE-0-2026-78553)

Tags

Sightings

Nomenclature