Security readout for executives and security teams
Plain-English summary
This affects WordPress sites using Webba Booking plugin version 4.2.21 or earlier. An authenticated administrator-level user could store script content that runs when another user views the affected page. Business impact is limited by the high privilege requirement, but compromised admin accounts or insider misuse could expose data or alter page behavior.
Executive priority
Treat as a moderate-priority WordPress plugin issue. It is not cited as actively exploited, but affected public websites should still be updated through normal vulnerability management, especially where admin accounts are shared or weakly protected.
Technical view
CVE-2021-36847 is an authenticated stored XSS in WebbaPlugins Webba Booking for WordPress, versions <= 4.2.21. CVSS 3.1 is 4.8: network reachable, low complexity, high privileges required, user interaction required, changed scope, low confidentiality and integrity impact, no availability impact. CWE-79 applies.
Likely exposure
Exposure is limited to WordPress installations with the Webba Booking plugin installed at version 4.2.21 or earlier. The source bundle does not identify exposure for other products, forks, or CPEs.
Exploitation context
The bundle does not cite active exploitation, and KEV status is false. Exploitation requires authenticated administrator-level access plus user interaction, which reduces likelihood but makes compromised admin accounts a relevant scenario.
Researcher notes
Evidence is limited to the CVE record, Patchstack reference, and WordPress plugin developer reference. The source bundle does not provide payload details, indicators of compromise, or a named fixed version. Avoid assuming exploitability beyond authenticated admin+ stored XSS against <= 4.2.21.
Mitigation direction
- Inventory WordPress sites for Webba Booking plugin usage.
- Prioritize moving any <= 4.2.21 installation off the affected version.
- Check WebbaPlugins, WordPress.org, or Patchstack guidance for the patched release.
- Restrict WordPress administrator access to trusted, MFA-protected accounts.
- Review stored booking/plugin content created by administrator accounts.
Validation and detection
- Confirm whether Webba Booking is installed on each WordPress site.
- Record the installed plugin version and flag versions <= 4.2.21.
- Review administrator accounts for unnecessary or stale privileges.
- Check recent admin changes to plugin settings or stored content.
- Document remediation status and remaining vendor guidance gaps.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-36847 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 4.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N1.72.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.8MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://patchstack.com/database/vulnerability/webba-booking-lite/wordpress-webba-booking-plugin-4-2-21-authenticated-stored-cross-site-scripting-xss-vulnerabilityCVE reference · x_refsource_CONFIRM
- https://wordpress.org/plugins/webba-booking-lite/#developersCVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.