CVE-2021-35243

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under NVD CVSS v3. EPSS exploit probability: 0.6%, top 30% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 5.3Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

The HTTP PUT and DELETE methods were enabled in the Web Help Desk web server (12.7.7 and earlier), allowing users to execute dangerous HTTP requests. The HTTP PUT method is normally used to upload data that is saved on the server with a user-supplied URL. While the DELETE method requests that the origin server removes the association between the target resource and its current functionality. Improper use of these methods may lead to a loss of integrity.

CVSS v3
5.3
EG Score
5.3(medium)
EPSS
55.9%
KEV
Not listed

Published

December 23, 2021

Last Modified

November 21, 2024

References (4)

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 43× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 14:06 UTCEPSS rescore
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  71. 2026-05-26 05:50 UTCEG score recompute
  72. 2026-05-26 05:50 UTCGHSA enrichment
  73. 2026-05-24 11:51 UTCOSV refresh

Frequently asked(5)

What is CVE-2021-35243?
CVE-2021-35243 is a medium vulnerability published on December 23, 2021. The HTTP PUT and DELETE methods were enabled in the Web Help Desk web server (12.7.7 and earlier), allowing users to execute dangerous HTTP requests. The HTTP PUT method is normally used to upload data that is saved on the server with a user-supplied URL. While the DELETE method requests that the…
When was CVE-2021-35243 disclosed?
CVE-2021-35243 was first published in the National Vulnerability Database on December 23, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-35243 actively exploited?
CVE-2021-35243 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 55.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-35243?
CVE-2021-35243 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2021-35243?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-35243, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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