CVE-2021-4253

MEDIUMNVD 3.56.1▲
EchelonGraph scoreMEDIUM confidence

Score 6.1 from GitHub Security Advisory published 2022-12-19. NVD baseline CVSS 3.5; sources differ by 2.6.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 3.5Exploit: None knownExposed services: Not assessed

A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).

A vulnerability, which was classified as problematic, was found in ctrlo lenio. Affected is an unknown function in the library lib/Lenio.pm of the component Ticket Handler. The manipulation of the argument site_id leads to cross site scripting. It is possible to launch the attack remotely. The name of the patch is 7a1f90bd2a0ce95b8338ec0926902da975ec64d9. It is recommended to apply a patch to fix this issue. VDB-216210 is the identifier assigned to this vulnerability.

CVSS v3
3.5
EG Score
6.1MEDIUMmedium confidence
EG Risk
28
EG Risk 28/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity61% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation.
EPSS PROB
0.4%
EPSS %ILE
32nd
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

December 18, 2022

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 8× in last 7d / 31× 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.

Showing the most recent 100 of 179 total refreshes for this CVE.

  1. 2026-10-09 20:04 UTCEPSS rescore
  2. 2026-10-08 16:40 UTCEPSS rescore
  3. 2026-10-07 23:45 UTCEPSS rescore
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  9. 2026-10-02 16:23 UTCEPSS rescore
  10. 2026-09-30 15:42 UTCEG score recompute
  11. 2026-09-30 15:00 UTCEPSS rescore
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  13. 2026-09-28 13:47 UTCEPSS rescore
  14. 2026-09-26 15:54 UTCEPSS rescore
  15. 2026-09-26 00:21 UTCEPSS rescore
  16. 2026-09-24 14:00 UTCEPSS rescore
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  18. 2026-09-24 03:01 UTCOSV refresh
  19. 2026-09-23 13:45 UTCEPSS rescore
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  21. 2026-09-21 20:28 UTCEPSS rescore
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  24. 2026-09-18 19:24 UTCEPSS rescore
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  1. 2026-09-16 14:05 UTCEPSS rescore
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  3. 2026-09-15 03:06 UTCEPSS rescore
  4. 2026-09-12 14:57 UTCEPSS rescore
  5. 2026-09-11 14:49 UTCEPSS rescore
  6. 2026-09-11 09:33 UTCEPSS rescore
  7. 2026-09-08 21:57 UTCEPSS rescore
  8. 2026-09-07 15:58 UTCEPSS rescore
  9. 2026-09-06 13:45 UTCEPSS rescore
  10. 2026-09-05 15:25 UTCEPSS rescore
  11. 2026-09-04 20:29 UTCOSV refresh
  12. 2026-09-04 13:57 UTCEPSS rescore
  13. 2026-09-04 05:03 UTCEPSS rescore
  14. 2026-09-02 14:09 UTCEPSS rescore
  15. 2026-09-01 13:51 UTCEPSS rescore
  16. 2026-08-30 19:14 UTCEPSS rescore
  17. 2026-08-30 01:19 UTCEPSS rescore
  18. 2026-08-28 21:38 UTCEPSS rescore
  19. 2026-08-27 14:22 UTCEPSS rescore
  20. 2026-08-26 14:43 UTCEPSS rescore
  21. 2026-08-25 13:46 UTCEPSS rescore
  22. 2026-08-24 14:13 UTCEPSS rescore
  23. 2026-08-21 23:46 UTCEPSS rescore
  24. 2026-08-20 22:52 UTCEPSS rescore
  25. 2026-08-19 17:01 UTCEPSS rescore
  26. 2026-08-18 13:45 UTCEPSS rescore
  27. 2026-08-18 07:34 UTCOSV refresh
  28. 2026-08-17 13:44 UTCEPSS rescore
  29. 2026-08-16 14:53 UTCEPSS rescore
  30. 2026-08-16 02:11 UTCEPSS rescore
  31. 2026-08-15 01:27 UTCEPSS rescore
  32. 2026-08-13 21:57 UTCEPSS rescore
  33. 2026-08-12 13:48 UTCEPSS rescore
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  35. 2026-08-09 13:44 UTCEPSS rescore
  36. 2026-08-08 16:34 UTCEPSS rescore
  37. 2026-08-07 16:24 UTCEPSS rescore
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  39. 2026-08-05 19:15 UTCEPSS rescore
  40. 2026-08-04 15:06 UTCEPSS rescore
  41. 2026-08-04 10:34 UTCEPSS rescore
  42. 2026-08-03 10:33 UTCEPSS rescore
  43. 2026-08-03 02:57 UTCOSV refresh
  44. 2026-08-02 02:24 UTCEPSS rescore
  45. 2026-08-01 04:13 UTCEPSS rescore
  46. 2026-07-30 16:25 UTCEPSS rescore
  47. 2026-07-30 01:28 UTCEPSS rescore
  48. 2026-07-28 15:33 UTCEPSS rescore
  49. 2026-07-26 14:52 UTCEPSS rescore
  50. 2026-07-25 14:15 UTCEPSS rescore
  51. 2026-07-24 14:15 UTCEPSS rescore
  52. 2026-07-24 14:15 UTCEPSS rescore
  53. 2026-07-23 14:16 UTCEPSS rescore
  54. 2026-07-23 02:04 UTCEG score recompute
  55. 2026-07-22 22:51 UTCEG score recompute
  56. 2026-07-22 14:06 UTCEPSS rescore
  57. 2026-07-21 15:22 UTCEPSS rescore
  58. 2026-07-21 15:22 UTCEPSS rescore
  59. 2026-07-20 17:05 UTCEPSS rescore
  60. 2026-07-19 14:29 UTCEPSS rescore
  61. 2026-07-19 02:27 UTCEPSS rescore
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  63. 2026-07-18 10:02 UTCEPSS rescore
  64. 2026-07-16 17:00 UTCEPSS rescore
  65. 2026-07-16 17:00 UTCEPSS rescore
  66. 2026-07-16 11:53 UTCOSV refresh
  67. 2026-07-15 16:55 UTCEPSS rescore
  68. 2026-07-15 01:58 UTCEPSS rescore
  69. 2026-07-15 01:58 UTCEPSS rescore
  70. 2026-07-13 22:27 UTCEPSS rescore
  71. 2026-07-13 06:11 UTCEPSS rescore
  72. 2026-07-13 06:11 UTCEPSS rescore
  73. 2026-07-12 05:44 UTCEPSS rescore
  74. 2026-07-11 08:25 UTCEPSS rescore
  75. 2026-07-09 19:07 UTCEPSS rescore

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Frequently asked(5)

What is CVE-2021-4253?
CVE-2021-4253 is a medium vulnerability published on December 18, 2022. A vulnerability, which was classified as problematic, was found in ctrlo lenio. Affected is an unknown function in the library lib/Lenio.pm of the component Ticket Handler. The manipulation of the argument site_id leads to cross site scripting. It is possible to launch the attack remotely. The name…
When was CVE-2021-4253 disclosed?
CVE-2021-4253 was first published on December 18, 2022, 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-2021-4253 actively exploited?
CVE-2021-4253 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (32nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-4253?
CVE-2021-4253 has a CVSS v3 base score of 3.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 6.1 (MEDIUM).
How do I remediate CVE-2021-4253?
A fix for CVE-2021-4253 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

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