Cyber Resilience

CVE-2025-6216

Auth Bypass in Alltena Allegra 7.0.0 – 7.5.2.70

Published
21 June 2025
Modified
17 June 2026
Patch / advisory
CVSS Score v3 9.8
Click a component to see what it means
Raw vectorCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.35 98th percentile
Risk Priority 92 floored blend · peak EPSS

Summary

CVE-2025-6216 is a critical-severity Weak Password Recovery Mechanism for Forgotten Password (CWE-640) vulnerability in Alltena Allegra. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Valid Accounts (T1078); ranked in the top 2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to IA-12 (Identity Proofing) and IA-5 (Authenticator Management) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

Allegra contains an authentication bypass vulnerability in its password recovery mechanism, specifically within the calculateTokenExpDate function used to generate reset tokens. The flaw stems from reliance on a predictable value rather than a secure random one, enabling attackers to forge valid tokens. It affects multiple versions of the Allegra application prior to the fixes noted in the vendor's release documentation.

Remote, unauthenticated attackers can exploit the issue over the network to bypass authentication entirely and gain unauthorized access to affected installations. Successful exploitation allows full compromise of user accounts through the password reset process, with no user interaction or credentials required. The vulnerability received a CVSS v3 score of 9.8 and is tracked as ZDI-CAN-27104.

Vendor advisories recommend upgrading to Allegra release 8.1.4 or 7.5.2, as detailed in the official release notes. The corresponding Zero Day Initiative advisory ZDI-25-410 provides additional technical context on the flaw.

The EPSS score rose from lower values to a peak of 0.5306 on 2026-04-29 before receding to the current 0.4984, indicating emerging exploitation interest after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Allegra calculateTokenExpDate Password Recovery Authentication Bypass Vulnerability. This vulnerability allows remote attackers to bypass authentication on affected installations of Allegra. Authentication is not required to exploit this vulnerability. The specific flaw exists within the password recovery mechanism. The issue results…

more

from reliance upon a predictable value when generating a password reset token. An attacker can leverage this vulnerability to bypass authentication on the application. Was ZDI-CAN-27104.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1078 Valid Accounts Stealth
Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
T1110.001 Password Guessing Credential Access
Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-51638Same product: Alltena Allegra
CVE-2023-51644Same product: Alltena Allegra
CVE-2024-5580Same product: Alltena Allegra
CVE-2023-51639Same product: Alltena Allegra
CVE-2023-52334Same product: Alltena Allegra
CVE-2023-51647Same product: Alltena Allegra
CVE-2025-3486Same product: Alltena Allegra
CVE-2023-52332Same product: Alltena Allegra
CVE-2024-30372Same product: Alltena Allegra
CVE-2025-3485Same product: Alltena Allegra

Affected Assets

alltena
allegra
7.0.0 — 7.5.2.70 · 8.0.0 — 8.1.24

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V7.4.3

Mitigating Controls (NIST 800-53 r5) AI

Identity proofing at appropriate assurance levels ensures forgotten-password recovery cannot succeed without strong verification of the user.

Authenticator management requires secure distribution, reset, and verification procedures that directly address weak password recovery flows.

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-01 mostly match
prevents

Credential lifecycle management directly includes password reset/recovery flows.

PR.AA-02 mostly match
prevents

Identity proofing is the core control that prevents weak or bypassed recovery mechanisms.

PR.AA-03 partial match
prevents

Authentication policy covers strength/MFA but does not address recovery path weaknesses.

PR.PS-06 partial match
prevents

Secure SDLC reduces implementation flaws but is not specific to password-recovery design.

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.

degrades

Strong authentication-information lifecycle rules directly address weak password-recovery flows.

prevents

Secure-SDLC practices can embed strong recovery design, yet the control is broader than this single weakness.

prevents

Application-security requirements can mandate secure recovery flows, but the control covers many other requirements.

prevents

Secure-coding standards can prevent weak recovery implementations, yet the control is wider in scope.

mitigates

Secure-authentication requirements include robust forgotten-password procedures.

none

Proper access-rights provisioning can limit who can trigger recovery, but does not fix the recovery mechanism itself.

References