Security readout for executives and security teams
Plain-English summary
CVE-2021-38351 is reflected cross-site scripting in the OSD Subscribe WordPress plugin up to 1.2.3. An attacker could cause a victim to open crafted content that makes script run in the victim's browser. The business impact is usually account/session risk and site administration disruption, not server takeover by itself.
Executive priority
Handle during normal vulnerability remediation cycles, faster for sites where WordPress administrators use shared or high-privilege accounts. The issue is moderate severity and user-interaction dependent, but browser-based compromise of an administrator can still create meaningful operational risk.
Technical view
The flaw is CWE-79 reflected XSS via the osd_subscribe_message parameter in osd_subscribe_options_subscribers.php. CVSS 3.1 is 6.1 with network attack vector, low complexity, no privileges required, required user interaction, changed scope, low confidentiality and integrity impact, and no availability impact.
Likely exposure
Exposure is limited to WordPress sites running OSD Subscribe version 1.2.3 or earlier. The source bundle does not identify other affected products, fixed versions, or required WordPress roles for the vulnerable path.
Exploitation context
The bundle marks this CVE as not in CISA KEV and provides no evidence of active exploitation. Exploitation still requires a user action, consistent with reflected XSS. Treat internet-facing WordPress administration workflows as higher concern because successful script execution may affect privileged users.
Researcher notes
Evidence is specific to OSD Subscribe <= 1.2.3 and the osd_subscribe_message parameter. The provided sources do not name a patch, exploit campaign, or broader product impact. Avoid expanding the affected set without additional vendor evidence.
Mitigation direction
- Inventory WordPress sites for OSD Subscribe and record installed versions.
- Disable or remove OSD Subscribe if it is version 1.2.3 or earlier.
- Check official plugin or vendor guidance for any fixed release before re-enabling.
- Prioritize administrator awareness around untrusted links until remediation is complete.
Validation and detection
- Confirm whether OSD Subscribe is installed on each WordPress site.
- Verify the installed plugin version is not 1.2.3 or earlier.
- Review web logs for requests referencing osd_subscribe_message.
- Confirm remediation by documenting plugin removal, disablement, or vendor-supported update.
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-2021-38351 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://www.wordfence.com/vulnerability-advisories/#CVE-2021-38351CVE reference · x_refsource_MISC
- https://plugins.trac.wordpress.org/browser/osd-subscribe/tags/1.2.3/options/osd_subscribe_options_subscribers.php#L86CVE 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.