AppointmentsWordPress extension · Wpmudev
CVE-2017-20206
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 · uneditedThe Appointments plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 2.2.1 via deserialization of untrusted input from the `wpmudev_appointments` cookie. This allows unauthenticated attackers to inject a PHP Object. Attackers were actively exploiting this vulnerability with the WP_Theme() class to create backdoors.
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 · high confidenceThe Appointments WordPress plugin versions up to 2.2.1 contains a PHP Object Injection vulnerability caused by insecure deserialization of untrusted input from the `wpmudev_appointments` cookie. Unauthenticated attackers can inject arbitrary PHP objects, and threat actors actively exploited this using the WP_Theme() class to create malicious backdoors.
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
AppointmentsWordPress extension
<= 2.2.1CVSS 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.
-
Check installed plugin versionIn WordPress admin, go to Plugins > Installed Plugins > Appointments (by WPMU DEV) and look at the version number. Alternatively, check the plugin's main PHP file header or the plugin directory name in wp-content/plugins/appointments/Affected if Version is 2.2.1 or lower (any version up to and including 2.2.1)
-
Verify plugin is activeCheck if the Appointments plugin is activated in WordPress admin under Plugins > Installed PluginsAffected if Plugin is active and version is vulnerable (2.2.1 or lower)
-
Inspect for suspicious filesCheck wp-content/themes/ directory for newly created or modified PHP files, especially theme files with backdoor code. Look for files with unusual names or recent modification datesAffected if Any unfamiliar PHP files exist in themes directory, particularly those containing base64_decode, eval, or shell execution functions
-
Review cookie handlingIf you have access to server logs or can inspect browser cookies, check for presence of wpmudev_appointments cookie with serialized PHP dataAffected if The wpmudev_appointments cookie exists and contains serialized (O:...) data
User is affected if the Appointments plugin version is 2.2.1 or lower and the plugin is currently active.
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.
dbcve · scopedUpdate the Appointments plugin to version 2.2.2 or later to patch the insecure deserialization. If immediate update is not possible, consider disabling the plugin until patched.
Appointments plugin version 2.2.2 or later
- Log in to WordPress admin dashboard
- Navigate to Plugins > Installed Plugins
- Find the Appointments plugin
- If an update is available, click 'Update Now' to update to version 2.2.2 or later
- Alternatively, manually upload the fixed plugin version from the WordPress plugin repository
- After updating, verify the plugin version is 2.2.2 or higher under Plugins > Installed Plugins
- Review site for any suspicious files or backdoors created during the exploitation period
- Consider resetting all user passwords as a precaution since the vulnerability allowed unauthenticated code execution
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Appointments
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-20206 — 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-2017-20206 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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