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CVE Record

CVE-2021-37393: In RPCMS v1.8 and below, the "nickname" variable is not properly sanitized before being displayed on page.

In RPCMS v1.8 and below, the "nickname" variable is not properly sanitized before being displayed on page. Attacker can use "update password" function to inject XSS payloads into nickname variable, and achieve stored XSS. Users who view the articles published by the injected user will trigger the XSS.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

RPCMS v1.8 and earlier may store unsafe content in a user nickname and show it to other users. If abused, visitors viewing articles from that user could have script run in their browser. The sources do not provide a CVSS score, confirmed fix, or evidence of active exploitation.

Executive priority

Prioritize if RPCMS is internet-facing or used by multiple untrusted users. Business risk is session theft, account abuse, or phishing through trusted pages. If RPCMS is not deployed, no action is needed beyond documentation.

Technical view

The reported issue is stored cross-site scripting caused by insufficient sanitization of the nickname variable before display. The CVE description says the update password function can be used to place malicious content into nickname, which later executes when users view articles published by that account.

Likely exposure

Exposure is limited to organizations running RPCMS v1.8 or below, particularly where users can update their account nickname and publish articles that other users view. The CVE source bundle lists affected vendor and product metadata as unavailable.

Exploitation context

The public description identifies a stored XSS path, but the provided sources do not show CISA KEV listing, active exploitation, broad scanning, or exploit maturity beyond a public reference gist.

Researcher notes

Evidence is narrow: the CVE text names RPCMS v1.8 and below and the nickname display path, but omits CVSS, CWE, CPE, vendor patch status, and exploitation confirmation. Validate against the referenced repository and proof-of-concept source without relying on inferred product metadata.

Mitigation direction

  • Inventory any RPCMS deployments and determine whether they are v1.8 or earlier.
  • Check the RPCMS repository or maintainer guidance for a fixed release or advisory.
  • Treat nickname and profile fields as untrusted data in templates.
  • Apply output encoding or sanitization before displaying nickname values.
  • Limit untrusted user publishing until remediation is verified.

Validation and detection

  • Review RPCMS version and deployment ownership records.
  • Inspect templates or views that render nickname values on article pages.
  • Confirm nickname updates cannot persist executable browser content.
  • Check logs for suspicious nickname changes around article publication.
  • Verify remediation with a safe stored-XSS regression test.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Credential and access behavior lookup

The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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CVE-2021-37393 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

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