CVE-2021-35237

MEDIUMNVD 5.04.3▼
EchelonGraph scoreMEDIUM confidence

Score 4.3 from GitHub Security Advisory published 2022-05-24. NVD baseline CVSS 5.0; sources differ by 0.7.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 5.0Exploit: NoneExposed: 0

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

A missing HTTP header (X-Frame-Options) in Kiwi Syslog Server has left customers vulnerable to click jacking. Clickjacking is an attack that occurs when an attacker uses a transparent iframe in a window to trick a user into clicking on an actionable item, such as a button or link, to another server in which they have an identical webpage. The attacker essentially hijacks the user activity intended for the original server and sends them to the other server. This is an attack on both the user and the server.

CVSS v3
5.0
EG Score
4.3(medium)
EPSS
56.4%
KEV
Not listed

Published

October 29, 2021

Last Modified

November 21, 2024

References (4)

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× 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. 2026-07-11 08:25 UTCEPSS rescore
  2. 2026-07-11 08:25 UTCEPSS rescore
  3. 2026-07-09 19:07 UTCEPSS rescore
  4. 2026-07-08 15:12 UTCEPSS rescore
  5. 2026-07-07 13:43 UTCEPSS rescore
  6. 2026-07-06 16:25 UTCEPSS rescore
  7. 2026-07-06 02:21 UTCEPSS rescore
  8. 2026-07-05 02:28 UTCEPSS rescore
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  10. 2026-07-04 06:29 UTCEPSS rescore
  11. 2026-07-04 06:29 UTCEPSS rescore
  12. 2026-07-01 15:04 UTCEPSS rescore
  13. 2026-06-30 23:20 UTCEPSS rescore
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  15. 2026-06-29 14:04 UTCEPSS rescore
  16. 2026-06-28 14:05 UTCEPSS rescore
  17. 2026-06-28 04:54 UTCEPSS rescore
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  19. 2026-06-27 03:06 UTCEPSS rescore
  20. 2026-06-25 13:48 UTCEPSS rescore
  21. 2026-06-25 13:48 UTCEPSS rescore
  22. 2026-06-24 14:03 UTCEPSS rescore
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  24. 2026-06-23 21:31 UTCEPSS rescore
  25. 2026-06-23 21:31 UTCEPSS rescore
Show 54 more
  1. 2026-06-22 14:24 UTCEPSS rescore
  2. 2026-06-22 14:24 UTCEPSS rescore
  3. 2026-06-21 14:55 UTCEPSS rescore
  4. 2026-06-21 01:58 UTCEPSS rescore
  5. 2026-06-21 01:58 UTCEPSS rescore
  6. 2026-06-19 19:24 UTCEPSS rescore
  7. 2026-06-19 19:24 UTCEPSS rescore
  8. 2026-06-18 17:51 UTCEPSS rescore
  9. 2026-06-18 17:51 UTCEPSS rescore
  10. 2026-06-17 17:51 UTCEPSS rescore
  11. 2026-06-16 17:51 UTCEPSS rescore
  12. 2026-06-16 17:51 UTCEPSS rescore
  13. 2026-06-15 17:46 UTCEPSS rescore
  14. 2026-06-14 23:15 UTCEPSS rescore
  15. 2026-06-13 22:58 UTCEPSS rescore
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  17. 2026-06-12 23:10 UTCEPSS rescore
  18. 2026-06-12 23:10 UTCEPSS rescore
  19. 2026-06-11 13:58 UTCEPSS rescore
  20. 2026-06-10 22:16 UTCEPSS rescore
  21. 2026-06-10 13:20 UTCEPSS rescore
  22. 2026-06-08 14:15 UTCEPSS rescore
  23. 2026-06-08 14:15 UTCEPSS rescore
  24. 2026-06-07 15:23 UTCEPSS rescore
  25. 2026-06-07 15:23 UTCEPSS rescore
  26. 2026-06-06 13:46 UTCEPSS rescore
  27. 2026-06-06 13:46 UTCEPSS rescore
  28. 2026-06-06 13:46 UTCEPSS rescore
  29. 2026-06-05 22:45 UTCEPSS rescore
  30. 2026-06-05 06:09 UTCEPSS rescore
  31. 2026-06-05 06:09 UTCEPSS rescore
  32. 2026-06-04 13:10 UTCEPSS rescore
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  34. 2026-06-02 20:11 UTCEPSS rescore
  35. 2026-06-02 20:11 UTCEPSS rescore
  36. 2026-06-01 13:50 UTCEPSS rescore
  37. 2026-06-01 13:50 UTCEPSS rescore
  38. 2026-05-31 22:29 UTCEPSS rescore
  39. 2026-05-31 22:29 UTCEPSS rescore
  40. 2026-05-31 00:15 UTCEPSS rescore
  41. 2026-05-31 00:15 UTCEPSS rescore
  42. 2026-05-29 13:42 UTCEPSS rescore
  43. 2026-05-29 13:42 UTCEPSS rescore
  44. 2026-05-28 13:43 UTCEPSS rescore
  45. 2026-05-28 13:43 UTCEPSS rescore
  46. 2026-05-27 13:39 UTCEPSS rescore
  47. 2026-05-27 13:39 UTCEPSS rescore
  48. 2026-05-27 13:39 UTCEPSS rescore
  49. 2026-05-26 13:42 UTCEPSS rescore
  50. 2026-05-26 08:18 UTCEG score recompute
  51. 2026-05-26 08:18 UTCGHSA enrichment
  52. 2026-05-26 07:17 UTCEPSS rescore
  53. 2026-05-26 07:17 UTCEPSS rescore
  54. 2026-05-26 07:17 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-35237?
CVE-2021-35237 is a medium vulnerability published on October 29, 2021. A missing HTTP header (X-Frame-Options) in Kiwi Syslog Server has left customers vulnerable to click jacking. Clickjacking is an attack that occurs when an attacker uses a transparent iframe in a window to trick a user into clicking on an actionable item, such as a button or link, to another server…
When was CVE-2021-35237 disclosed?
CVE-2021-35237 was first published in the National Vulnerability Database on October 29, 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-2021-35237 actively exploited?
CVE-2021-35237 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 56.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-35237?
CVE-2021-35237 has a CVSS v3 base score of 5.0 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 4.3.
How do I remediate CVE-2021-35237?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-35237, 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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