Incorrect AuthorizationWeakness · CWE-863

CVE-2020-36948

CRITICAL · 9.8 CVSS v3.1 Published 2026-01-27
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
VestaCP 0.9.8-26 contains a session token vulnerability in the LoginAs module that allows remote attackers to manipulate authentication tokens. Attackers can exploit insufficient token validation to access user accounts and perform unauthorized login requests without proper administrative permissions.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

VestaCP 0.9.8-26 contains a session token vulnerability in the LoginAs module where authentication tokens are insufficiently validated, allowing remote attackers to manipulate tokens and gain unauthorized access to user accounts without proper administrative permissions.

MitigationUpgrade VestaCP to a patched version and audit all user sessions and account access for any unauthorized activity stemming from this vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed VestaCP version
    Run command: v-list-sys-release or cat /usr/local/vesta/conf/vesta.conf | grep VERSION
    Affected if Version is 0.9.8-26 (exact match indicates vulnerability; versions lower than this in the 0.9.8.x line may also be affected)
  2. Identify LoginAs module presence
    Locate LoginAs-related files: find /usr/local/vesta -name '*login*as*' -o -name '*loginas*' 2>/dev/null; check for /usr/local/vesta/web/login/ directory
    Affected if LoginAs module files exist in the installation (vulnerability is only applicable if this module is present)
  3. Verify LoginAs functionality is enabled
    Check VestaCP configuration: cat /usr/local/vesta/conf/vesta.conf | grep -i loginas; also check /usr/local/vesta/conf/httpd.conf or /usr/local/vesta/conf/nginx.conf for LoginAs-related directives
    Affected if LoginAs feature is enabled in the VestaCP configuration (vulnerability requires this feature to be active)
  4. Inspect session token validation in LoginAs code
    Examine the LoginAs PHP handler: cat /usr/local/vesta/web/login/index.php (or find the specific login-as handler) and look for token validation logic, checking if tokens are validated for randomness, expiration, and integrity before allowing login
    Affected if Code shows weak or missing session token validation (insufficient cryptographic randomness, no expiration checks, or missing integrity validation)
  5. Check for recent authentication logs indicating LoginAs abuse
    Review VestaCP auth logs: cat /var/log/vesta/auth.log or /usr/local/vesta/log/auth.log | grep -i 'login.*as\|sudoas\|became' for suspicious login-as activity without proper admin sessions
    Affected if Logs show LoginAs usage occurring without corresponding admin session tokens or with malformed tokens

A user is affected if VestaCP version 0.9.8-26 is installed AND the LoginAs module is enabled with weak or missing session token validation in its authentication logic

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade VestaCP to a patched version and audit all user sessions and account access for any unauthorized activity stemming from this vulnerability.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-36948 in production — separate from our analysis above.

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What this is

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What belongs here
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