CVE-2025-64349: Elog Authentication Bypass Vulnerability

CVE-2025-64349 Overview

CVE-2025-64349 affects ELOG, an open-source electronic logbook application maintained by the ritt/elog project. The vulnerability allows an authenticated user to modify another user's profile attributes, including the target's email address. Once the email is changed, the attacker can trigger a password reset flow and seize control of the victim account. The flaw is classified as Missing Authorization [CWE-862]. By default, ELOG does not permit self-registration, so the attacker must already hold valid credentials on the affected instance.

Critical Impact
Any authenticated ELOG user can take over arbitrary accounts, including administrator accounts, by rewriting a target's email address and requesting a password reset.

Affected Products

ELOG (elog_project:elog) versions prior to the patched commits
Self-hosted ELOG deployments using the default authentication backend
ELOG instances exposed to authenticated internal or external users

Discovery Timeline

2025-10-31 - CVE-2025-64349 published to NVD
2025-11-10 - Last updated in NVD database

Technical Details for CVE-2025-64349

Vulnerability Analysis

ELOG exposes user profile management endpoints that update fields such as username, full name, and email address. The endpoints accept the target user identifier from the request but fail to verify that the requester owns the profile being modified or holds administrator privileges. This Missing Authorization condition lets any authenticated user submit profile edits for any other user on the instance.

The email field is the highest-value target because ELOG ties the password reset flow to the address stored in the user record. After overwriting the email address on a privileged account, the attacker requests a password reset, receives the reset token at an attacker-controlled mailbox, and chooses a new password. The original account holder loses access while the attacker obtains full session rights inheriting that account's roles and logbook permissions.

Root Cause

The root cause is missing server-side authorization checks on the user profile modification handlers. ELOG validated that the request came from an authenticated session but did not compare the session principal to the user record being edited. The upstream fixes are tracked in commits 7092ff64f6eb9521f8cc8c52272a020bf3730946 and f81e5695c40997322fe2713bfdeba459d9de09dc on the ELOG Bitbucket repository.

Attack Vector

Exploitation requires network access to the ELOG web interface and a low-privileged authenticated session. The attacker issues an HTTP request to the profile update endpoint with the victim's user identifier and a new email address under attacker control. The attacker then invokes the password reset endpoint for the victim's account, captures the emailed reset link, and completes the takeover. No user interaction from the victim is required. See the CVE-2025-64349 record for additional references.

Detection Methods for CVE-2025-64349

Indicators of Compromise

HTTP requests to ELOG profile-edit endpoints where the target user identifier does not match the session user identifier.
Email address changes on user records that are quickly followed by a password reset request for the same account.
Password reset emails routed to domains that differ from the organization's standard user email domains.
Successful logins to administrator or privileged ELOG accounts from new IP addresses immediately after a profile change.

Detection Strategies

Enable verbose ELOG access logging and alert on profile mutation requests originating from non-matching session identities.
Correlate profile update events with subsequent password reset events on the same user_id within a short time window.
Track changes to the email attribute on privileged accounts as a high-severity audit event.

Monitoring Recommendations

Forward ELOG web server and application logs to a centralized log platform for retention and correlation.
Monitor outbound mail server logs for password reset messages sent to external or uncommon domains.
Review user directory diffs on a recurring schedule to surface unauthorized email or role changes.

How to Mitigate CVE-2025-64349

Immediate Actions Required

Upgrade ELOG to a build that includes commits 7092ff64f6eb9521f8cc8c52272a020bf3730946 and f81e5695c40997322fe2713bfdeba459d9de09dc.
Audit all ELOG user accounts for unexpected email address changes and reset credentials for any account showing tampering.
Restrict ELOG access to trusted networks or place the application behind a VPN until patching is complete.
Rotate session secrets and force re-authentication for all users after applying the fix.

Patch Information

The ELOG maintainers addressed the missing authorization check in two Bitbucket commits. Administrators should rebuild or redeploy ELOG from a source tree that includes both the first authorization fix commit and the follow-up commit. Additional advisory context is published in the CISA CSAF document for this issue.

Workarounds

Disable the password reset workflow at the mail relay or reverse proxy layer until patches are deployed.
Limit ELOG accounts to a minimal trusted set and disable inactive accounts to reduce the authenticated attacker pool.
Place a reverse proxy in front of ELOG that enforces per-user authorization on profile edit URLs based on the authenticated session identifier.

bash

# Example reverse proxy guardrail: block profile edits where the URL user
# parameter does not match the session-bound username header.
# Adjust paths and header names to match your ELOG deployment.
location ~ ^/elog/.*/edit$ {
    if ($arg_unm != $http_x_authenticated_user) {
        return 403;
    }
    proxy_pass http://elog_backend;
}