Cyber Resilience

CVE-2024-6839

Flask-Cors Project Flask-Cors 4.0.1

Public PoC
Published
20 March 2025
Modified
03 November 2025
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0065 48th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2024-6839 is a medium-severity Improper Resolution of Path Equivalence (CWE-41) vulnerability in Flask-Cors Project Flask-Cors. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked at the 48th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and AC-3 (Access Enforcement) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

corydolphin/flask-cors version 4.0.1 contains an improper regex path matching vulnerability. The plugin prioritizes longer regex patterns over more specific ones when matching paths, which can lead to less restrictive CORS policies being applied to sensitive endpoints. This mismatch in regex…

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pattern priority allows unauthorized cross-origin access to sensitive data or functionality, potentially exposing confidential information and increasing the risk of unauthorized actions by malicious actors.

CWE(s)
CWE-41

Related Threats

MITRE ATT&CK Enterprise Techniques

T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
T1083 File and Directory Discovery Discovery
Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-6866Same product: Flask-Cors Project Flask-Cors
CVE-2024-6844Same product: Flask-Cors Project Flask-Cors
CVE-2023-46169Shared CWE-41
CVE-2024-30036Shared CWE-41
CVE-2025-21269Shared CWE-41
CVE-2025-21268Shared CWE-41
CVE-2025-43298Shared CWE-41
CVE-2025-58290Shared CWE-41
CVE-2026-5816Shared CWE-41
CVE-2025-21247Shared CWE-41

Affected Assets

flask-cors project
flask-cors
4.0.1

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation of file paths directly rejects or normalizes the special-character manipulations that create equivalent names.

AC-3 Access Enforcement partial match

Proper enforcement of file access authorizations structurally blocks disclosure when equivalent paths are presented.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent introduction of improper path-resolution logic in software.

PR.IR-01 partial match
prevents

Path-equivalence flaws enable unauthorized file access that network segmentation and logical access controls can partially block.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.28 Secure coding mostly match
prevents

Secure coding standards directly require canonical path resolution and input sanitization to prevent equivalence attacks.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect path-equivalence flaws before release, partially fulfilling the control.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle includes path-handling requirements that reduce equivalence-based disclosure.

A.8.26 Application security requirements partial match
prevents

Application security requirements can mandate canonicalization and input validation to block path equivalence.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles call for safe file-system abstractions that mitigate path traversal risks.

A.8.3 Information access restriction none match
none

Information access restriction limits what files can be reached, indirectly reducing impact of path-equivalence exploits.

References