Cyber Resilience

CVE-2025-66507

Auth Bypass in Fit2Cloud 1Panel ≤ 2.0.14

Auth Bypass
Published
09 December 2025
Modified
10 December 2025
Patch / advisory
View advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0046 38th percentile
Risk Priority 57 floored blend · peak EPSS

Summary

CVE-2025-66507 is a high-severity Authentication Bypass by Spoofing (CWE-290) vulnerability in Fit2Cloud 1Panel. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 38th 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 AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A06:2025 Insecure DesignA07:2025 Authentication Failures

EU & UK References

Vulnerability Data

1Panel is an open-source, web-based control panel for Linux server management. Versions 2.0.13 and below allow an unauthenticated attacker to disable CAPTCHA verification by abusing a client-controlled parameter. Because the server previously trusted this value without proper validation, CAPTCHA protections…

more

can be bypassed, enabling automated login attempts and significantly increasing the risk of account takeover (ATO). This issue is fixed in version 2.0.14.

CWE(s)
CWE-290CWE-602CWE-807

Related Threats

MITRE ATT&CK Enterprise Techniques

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 →
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
attack.mitre.org →
T1557.001 Name Resolution Poisoning and SMB Relay Credential Access
By responding to LLMNR/NBT-NS/mDNS network traffic, adversaries may spoof an authoritative source for name resolution to force communication with an adversary controlled system.
attack.mitre.org →
T1036 Masquerading Stealth
Adversaries may attempt to manipulate features of their artifacts to make them appear legitimate or benign to users and/or security tools.
attack.mitre.org →
T1036.001 Invalid Code Signature Stealth
Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool.
attack.mitre.org →
T1134 Access Token Manipulation Stealth
Adversaries may modify access tokens to operate under a different user or system security context to perform actions and bypass access controls.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-66508Same product: Fit2Cloud 1Panel
CVE-2024-24768Same product: Fit2Cloud 1Panel
CVE-2023-39966Same product: Fit2Cloud 1Panel
CVE-2023-39965Same product: Fit2Cloud 1Panel
CVE-2024-27288Same product: Fit2Cloud 1Panel
CVE-2023-39964Same product: Fit2Cloud 1Panel
CVE-2025-34410Same product: Fit2Cloud 1Panel
CVE-2025-34430Same product: Fit2Cloud 1Panel
CVE-2024-39907Same product: Fit2Cloud 1Panel
CVE-2024-39911Same product: Fit2Cloud 1Panel

Affected Assets

fit2cloud
1panel
≤ 2.0.14

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 4 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V10.7.1
  • V6.4.3
  • V10.4.16
  • V10.5.1

Mitigating Controls (NIST 800-53 r5) AI

AC-25 Reference Monitor good match

Requires a tamper-proof, always-invoked reference monitor that cannot be bypassed by client-side logic.

AC-3 Access Enforcement good match

Enforces all access decisions on the server according to policy rather than trusting client-supplied enforcement.

IA-2 Identification and Authentication (Organizational Users) good match

Proper unique identification and authentication of users directly stops spoofing-based bypass of authentication.

IA-3 Device Identification and Authentication good match

Device identification and authentication before connection prevents spoofing of devices to bypass auth.

IA-8 Identification and Authentication (Non-organizational Users) good match

Authentication of non-organizational users blocks external spoofing attempts against the scheme.

AC-24 Access Control Decisions good match

Explicitly requires that every access decision be based on authoritative, protected decision data rather than caller-supplied inputs.

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.AA-04 full match
prevents

Protecting, conveying, and verifying identity assertions specifically prevents the spoofing that enables authentication bypass.

PR.AA-03 mostly match
prevents

Requiring authentication of users/services/hardware directly counters spoofing-based bypass when strong methods are used.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent design flaws that place server security enforcement on the client.

PR.AA-01 partial match
prevents

Proper management of identities/credentials reduces the chance that security decisions will be driven by untrusted inputs.

PR.AA-02 partial match
prevents

Proofing and binding identities reduces spoofing opportunities during enrollment but does not address runtime authentication implementation flaws.

PR.AA-05 partial match
prevents

Proper policy-based enforcement of authorizations implies server-side controls rather than client-only checks.

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.8.5 Secure authentication full match
degrades

Secure authentication control directly mitigates authentication bypass by spoofing.

A.5.17 Authentication information mostly match
degrades

Authentication information management directly addresses credential handling that prevents spoofing.

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

Secure architecture principles discourage client-side trust but do not directly address this weakness.

A.8.28 Secure coding mostly match
prevents

Secure coding standards directly prohibit using untrusted inputs for security-critical decisions.

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

Security testing can detect spoofing vulnerabilities but does not prevent them by itself.

A.8.3 Information access restriction mostly match
prevents

Information access restriction is undermined when the client is trusted to enforce it.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-290
RHEL 7 (1 rule)
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-290
RHEL 8 (1 rule)
  • V-230492 RHEL 8 must not have the rsh-server package installed. prevents CWE-290

References