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    2 vulnerabilities by LaciSynchroni

    CVE-2026-54047 (GCVE-0-2026-54047)

    Vulnerability from nvd – Published: 2026-09-11 16:23 – Updated: 2026-09-11 19:17
    VLAI
    Title
    Laci Synchroni Backend Vulnerable to Account Takeover / User Impersonation via Client-Side Configuration Manipulation
    Summary
    Laci Synchroni is a decentralized mod and appearance sync server and plugin for Dalamud. Versions of the backend prior to 1.2.3 have an improper authentication vulnerability in the application's OAuth2 login flow. The application relies on client-side state by trusting the `UID` field inside the `Authentications` object of a user's local `config.json` file. By manually editing this local file on their PC prior to logging in, a user can supply an arbitrary UID. Because the server fails to validate that the authenticated OAuth2 identity matches the requested UID, an attacker can fully impersonate any target user and perform actions on their behalf. This issue has been resolved in version 1.2.3. The patch modifies `AuthorizeOauthAsync` inside the `SecretKeyAuthenticatorService` to strictly bind the lookup of the requested User ID (`requestedUid`) to the record of the successfully authenticated identity (`primaryUid`). The server will no longer load or return session tokens for a requested UID unless it matches the verified, authenticated database record. No known workarounds are available.
    Severity
    9.2 (Critical)
    CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
    SSVC
    Exploitation: none Automatable: no Technical Impact: total
    CISA Coordinator · CISA-ADP (v2.0.3)
    Decision recorded 2026-09-11 19:17 UTC
    CWE
    • CWE-287 - Improper Authentication
    • CWE-349 - Acceptance of Extraneous Untrusted Data With Trusted Data
    • CWE-602 - Client-Side Enforcement of Server-Side Security
    Assigner
    References
    Impacted products
    Vendor Product Version
    LaciSynchroni server Affected: < 1.2.3
    		Create a notification for this product.
    Show details on NVD website
    To clipboard 

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    CVE-2026-54047 (GCVE-0-2026-54047)

    Vulnerability from cvelistv5 – Published: 2026-09-11 16:23 – Updated: 2026-09-11 19:17
    VLAI
    Title
    Laci Synchroni Backend Vulnerable to Account Takeover / User Impersonation via Client-Side Configuration Manipulation
    Summary
    Laci Synchroni is a decentralized mod and appearance sync server and plugin for Dalamud. Versions of the backend prior to 1.2.3 have an improper authentication vulnerability in the application's OAuth2 login flow. The application relies on client-side state by trusting the `UID` field inside the `Authentications` object of a user's local `config.json` file. By manually editing this local file on their PC prior to logging in, a user can supply an arbitrary UID. Because the server fails to validate that the authenticated OAuth2 identity matches the requested UID, an attacker can fully impersonate any target user and perform actions on their behalf. This issue has been resolved in version 1.2.3. The patch modifies `AuthorizeOauthAsync` inside the `SecretKeyAuthenticatorService` to strictly bind the lookup of the requested User ID (`requestedUid`) to the record of the successfully authenticated identity (`primaryUid`). The server will no longer load or return session tokens for a requested UID unless it matches the verified, authenticated database record. No known workarounds are available.
    Severity
    9.2 (Critical)
    CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
    SSVC
    Exploitation: none Automatable: no Technical Impact: total
    CISA Coordinator · CISA-ADP (v2.0.3)
    Decision recorded 2026-09-11 19:17 UTC
    CWE
    • CWE-287 - Improper Authentication
    • CWE-349 - Acceptance of Extraneous Untrusted Data With Trusted Data
    • CWE-602 - Client-Side Enforcement of Server-Side Security
    Assigner
    References
    Impacted products
    Vendor Product Version
    LaciSynchroni server Affected: < 1.2.3
    		Create a notification for this product.
    Show details on NVD website
    To clipboard 

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