Security readout for executives and security teams
Plain-English summary
CVE-2021-43353 affects the Crisp Live Chat WordPress plugin through version 0.31. A missing CSRF nonce check could let an attacker trick an administrator into saving malicious script into plugin settings, creating stored XSS risk on the site.
Executive priority
Treat as high priority for internet-facing WordPress properties using the affected plugin. The business risk is site compromise through administrator-targeted deception, with potential confidentiality, integrity, and availability impact if malicious script is stored.
Technical view
The issue is CWE-352 in crisp_plugin_settings_page within crisp.php. Missing nonce validation permits a cross-site request forgery path that can inject arbitrary web scripts in affected plugin versions. The CVSS 3.1 score is 8.8 high with network access, low complexity, no attacker privileges, and user interaction required.
Likely exposure
Exposure is limited to WordPress sites running Crisp Live Chat version 0.31 or earlier. Sites not using this plugin, or using unaffected versions confirmed by vendor guidance, are not indicated as affected by the supplied sources.
Exploitation context
The supplied bundle does not show CISA KEV listing or cite active exploitation. Exploitation requires user interaction, likely involving a privileged WordPress user being induced to perform an action that changes plugin settings.
Researcher notes
Evidence identifies CSRF leading to stored XSS through the plugin settings page. The bundle names affected versions up to 0.31 but does not provide a complete remediation advisory or observed exploitation details. Avoid assuming active exploitation without additional cited evidence.
Mitigation direction
- Inventory WordPress sites for Crisp Live Chat plugin versions.
- Upgrade Crisp Live Chat after confirming vendor or WordPress plugin guidance.
- Disable or remove the plugin where upgrade cannot be promptly verified.
- Review plugin settings for unexpected script content.
- Limit WordPress administrator access to trusted users only.
Validation and detection
- Confirm whether any site runs Crisp Live Chat version 0.31 or earlier.
- Check plugin settings for unauthorized JavaScript or unfamiliar configuration values.
- Verify the installed version includes nonce validation for settings changes.
- Review WordPress admin activity around the publication and remediation window.
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-352: 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-2021-43353 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
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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:N/UI:R/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/vulnerability-advisories/#CVE-2021-43353CVE reference · x_refsource_MISC
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2643954%40crisp&new=2643954%40crisp&sfp_email=&sfph_mail=CVE reference · x_refsource_MISC
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.
Cross-Site Request Forgery (CSRF)
Cross-Site Request Forgery (CSRF) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.