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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-78553
StatePUBLISHED
AssignerCIRCL
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-24 20:17:24 UTC
Updated2026-08-24 20:17:24 UTC
DescriptionRansomLook 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.

Risk And Classification

Primary CVSS: v4.0 7 HIGH from 5a6e4751-2f3f-4070-9419-94fb35b644e8

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

Problem Types: CWE-276 | CWE-732 | CWE-276 CWE-276 Incorrect Default Permissions | CWE-732 CWE-732 Incorrect Permission Assignment for Critical Resource

VersionSourceTypeScoreSeverityVector
4.05a6e4751-2f3f-4070-9419-94fb35b644e8Secondary7HIGHCVSS: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/C...
4.0CNACVSS7HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Local
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Ransomlook Ransomlook affected 2.0.0 semver Not specified

References

ReferenceSourceLinkTags
github.com/RansomLook/RansomLook/commit/df9d47edcf02dd0125db869d5bc19d93... 5a6e4751-2f3f-4070-9419-94fb35b644e8 github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Jeroen Pinoy (en)

CNA: Fafner [_KeyZee_] (en)

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