Cyber Resilience

CVE-2025-52921

Published
23 June 2025
Modified
17 June 2026
CVSS Score v3.1 9.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
EPSS Score 0.0048 39th percentile
Risk Priority 68 floored blend · peak EPSS

Summary

CVE-2025-52921 is a critical-severity Unprotected Alternate Channel (CWE-420) vulnerability. Its CVSS base score is 9.9 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Fallback Channels (T1008); ranked at the 39th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-8 (Transmission Confidentiality and Integrity) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

In Innoshop through 0.4.1, an authenticated attacker could exploit the File Manager functions in the admin panel to achieve code execution on the server, by uploading a crafted file and then renaming it to have a .php extension by using…

more

the Rename Function. This bypasses the initial check that uploaded files are image files. The application relies on frontend checks to restrict the administrator from changing the extension of uploaded files to .php. This restriction is easily bypassed with any proxy tool (e.g., BurpSuite). Once the attacker renames the file, and gives it the .php extension, a GET request can be used to trigger the execution of code on the server.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1008 Fallback Channels Command And Control
Adversaries may use fallback or alternate communication channels if the primary channel is compromised or inaccessible in order to maintain reliable command and control and to avoid data transfer thresholds.
T1048 Exfiltration Over Alternative Protocol Exfiltration
Adversaries may steal data by exfiltrating it over a different protocol than that of the existing command and control channel.
T1048.003 Exfiltration Over Unencrypted Non-C2 Protocol Exfiltration
Adversaries may steal data by exfiltrating it over an un-encrypted network protocol other than that of the existing command and control channel.
T1571 Non-Standard Port Command And Control
Adversaries may communicate using a protocol and port pairing that are typically not associated.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-7266Shared CWE-420
CVE-2025-56558Shared CWE-420
CVE-2026-40435Shared CWE-420
CVE-2025-62001Shared CWE-420
CVE-2026-25916Shared CWE-420
CVE-2024-6242Shared CWE-420
CVE-2025-54309Shared CWE-420
CVE-2025-62820Shared CWE-420
CVE-2023-20198Shared CWE-420
CVE-2025-66432Shared CWE-420

Affected Assets

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Transmission confidentiality and integrity requirements apply to all transmitted data, preventing weaker protection on secondary channels.

Information flow enforcement requires consistent authorization and control over every path, directly stopping unequal protection of alternate channels.

Boundary protection mandates monitoring and control at all external and key internal interfaces, eliminating unprotected alternate channels.

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.DS-02 mostly match
prevents

Protecting all data-in-transit directly mitigates unequal channel protection though the control addresses broader transit scenarios.

PR.IR-01 mostly match
prevents

Network protection from unauthorized access inherently requires securing every channel, not just primaries.

DE.CM-01 partial match
prevents

Network monitoring can surface use of unprotected alternate channels but does not prevent the design flaw.

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.

prevents

Access restrictions may cover primary paths but leave alternate channels unprotected unless explicitly extended.

prevents

Secure authentication applies to primary channels but does not ensure alternate channels receive the same strength.

mitigates

Network security controls ensure all channels receive equivalent protection, directly addressing unprotected alternate channels.

prevents

Security of network services requires consistent protection across all service channels, mitigating alternate-channel weaknesses.

mitigates

Network segregation can reduce exposure of alternate channels but does not guarantee equivalent protection levels.

mitigates

Cryptography can protect alternate channels but does not address the policy of applying equal protection across channels.

References