Security readout for executives and security teams
Plain-English summary
CVE-2021-34640 is a reflected cross-site scripting issue in the Securimage-WP-Fixed WordPress plugin. Affected versions up to and including 3.5.4 can reflect attacker-supplied script through unsafe use of PHP_SELF. Successful abuse requires user interaction, but could expose session data or alter page behavior in a victim browser.
Executive priority
Treat this as a moderate website risk. It is not reported as actively exploited in the provided sources, but public WordPress sites using the vulnerable plugin should be remediated because XSS can affect users and administrators.
Technical view
The plugin's securimage-wp.php uses $_SERVER['PHP_SELF'] in a way that permits reflected script injection. The CVSS 3.1 score is 6.1 with network access, low complexity, no privileges, required user interaction, changed scope, and low confidentiality and integrity impact.
Likely exposure
Exposure is limited to WordPress sites running Securimage-WP-Fixed versions up to and including 3.5.4. The source bundle does not identify affected hosting platforms, themes, or other plugins.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. The issue is remotely reachable but reflected XSS typically requires persuading a user to open a crafted URL or otherwise interact with attacker-controlled content.
Researcher notes
Evidence supports CWE-79 reflected XSS in Securimage-WP-Fixed through PHP_SELF handling. The bundle does not provide a named patched version, exploit telemetry, or vendor advisory details beyond the Wordfence reference and WordPress plugin source link.
Mitigation direction
- Inventory WordPress sites for Securimage-WP-Fixed versions 3.5.4 or earlier.
- Check Wordfence and vendor guidance for an identified fixed release or supported remediation.
- Remove or replace the plugin if no maintained fixed version is available.
- Prioritize remediation on public sites with authenticated users or administrative traffic.
Validation and detection
- Confirm whether Securimage-WP-Fixed is installed and record the exact plugin version.
- Review the referenced securimage-wp.php area for unsafe PHP_SELF output.
- After remediation, verify the vulnerable plugin version is absent from production sites.
- Review web logs for suspicious requests targeting the plugin path.
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-2021-34640 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
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/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:N/UI:R/S:C/C:L/I:L/A:N2.82.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://plugins.trac.wordpress.org/browser/securimage-wp-fixed/trunk/securimage-wp.php#L628CVE reference · x_refsource_MISC
- https://www.wordfence.com/vulnerability-advisories/#CVE-2021-34640CVE 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.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.