Security readout for executives and security teams
Plain-English summary
ReCaptcha Solver 5.7 trusted responses from several CAPTCHA-solving services too much. If one of those services returned malicious HTML, the extension could place it into the browser page, potentially letting that service control the user’s browser session.
Executive priority
Treat this as a targeted browser-extension risk. It is not listed as actively exploited, but the impact could be serious for affected users because the vulnerable trust boundary is inside the browser.
Technical view
The issue is DOM-based XSS in setCaptchaCode(). Responses from Anti-Captcha.com, RuCaptcha.com, 2captcha.com, DEATHbyCAPTCHA.com, ImageTyperz.com, or BestCaptchaSolver.com are inserted as HTML rather than safely handled as text.
Likely exposure
Exposure is likely limited to users running ReCaptcha Solver 5.7 with the named CAPTCHA-solving services. The source bundle does not identify other affected versions, packages, browsers, or enterprise products.
Exploitation context
The bundle does not cite active exploitation, and KEV is false. The reported attack surface is the extension processing a malicious or compromised third-party CAPTCHA service response.
Researcher notes
Evidence is narrow: CVE description and one public report. No CVSS, CWE, patch version, or maintainer advisory is provided in the bundle. Avoid expanding affected scope beyond ReCaptcha Solver 5.7.
Mitigation direction
- Inventory browsers for ReCaptcha Solver 5.7 installations.
- Disable or remove the extension where business use is not required.
- Check the project or vendor guidance for a fixed release or official workaround.
- Restrict use of third-party CAPTCHA-solving services where policy allows.
- Review browser extension allowlists and block unsupported risky extensions.
Validation and detection
- Confirm whether ReCaptcha Solver 5.7 is installed on managed endpoints.
- Check extension configuration for the named CAPTCHA-solving services.
- Review browser extension inventory and policy enforcement logs.
- Look for unusual browser activity from affected users after CAPTCHA-solving use.
- Verify whether any vendor-fixed version is available before redeployment.
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.
CVE-2021-39362 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://thesamarkand.tumblr.com/post/660171228514009088/xss-vulnerability-in-recaptcha-solver-by-dozzCVE 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.