CVE-2021-20618
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 · uneditedPrivilege chaining vulnerability in acmailer ver. 4.0.2 and earlier, and acmailer DB ver. 1.1.4 and earlier allows remote attackers to bypass authentication and to gain an administrative privilege which may result in obtaining the sensitive information on the server via unspecified vectors.
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 confidenceA privilege chaining vulnerability in acmailer versions 4.0.2 and earlier (and acmailer DB versions 1.1.4 and earlier) allows remote attackers to bypass authentication mechanisms and escalate to administrative privileges, potentially exposing sensitive server information.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 4.0.2<= 1.1.4CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify acmailer versionCheck the software version displayed in the administration panel, or look for a version file in the installation directory (common locations: /version, /includes/version.php, or in the application's footer/about page). Compare against affected versions: <= 4.0.2 for acmailer or <= 1.1.4 for acmailer DB.Affected if Installed version is 4.0.2 or earlier (acmailer) or 1.1.4 or earlier (acmailer DB)
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Determine if application is network-accessibleVerify whether the acmailer web interface is reachable from external networks or the internet. Check firewall rules, reverse proxy configurations, or cloud security group settings that allow HTTP/HTTPS access to the server.Affected if The application is accessible from untrusted networks (internet or external subnets)
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Review admin user accountsAccess the user management section of the administration panel and enumerate all accounts with administrative privileges. Look for unexpected, disabled, or obsolete admin accounts that may indicate exploitation.Affected if There are admin accounts that were not created by legitimate administrators, or unexpected privilege assignments exist
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Check authentication logs for anomaliesReview server access logs and application authentication logs for unusual login patterns, especially successful logins from unfamiliar IP addresses or at unusual times that may indicate authentication bypass.Affected if There are successful admin logins from IP addresses not belonging to legitimate administrators
A user is affected if running acmailer version 4.0.2 or earlier (or acmailer DB 1.1.4 or earlier) and the application is network-accessible, as the privilege chaining flaw can be exploited remotely to gain admin access.
Generated from the published advisory. Verify against your own configuration.
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 dataUpgrade to the latest version of acmailer (4.0.3 or later for acmailer, 1.1.5 or later for acmailer DB). If immediate patching is not possible, restrict network access to the application and review authentication/authorization code for privilege escalation paths.
- Consultation2.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20618 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-20618 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data