CVE-2021-28164

HIGHNVD 5.38.8▲
EchelonGraph scoreHIGH confidence

Score elevated to 8.8 because EPSS predicts 82% probability of exploitation within the next 30 days (99th percentile of EPSS-scored CVEs). NVD baseline CVSS 5.3 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction (continuous uplift above 30%)
Sources: epss, nvd
Weaponized
8.8EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 82%
  • Public exploit code is available (Metasploit, epss top5pct, epss high, public exploit)
CISA-KEV: Not listedEPSS PROB: 82%CVSS: 5.3Exploit: Metasploit · epss top5pct · epss high · public exploitExposed services: Not assessed

A fix is available — apply it.

In Eclipse Jetty 9.4.37.v20210219 to 9.4.38.v20210224, the default compliance mode allows requests with URIs that contain %2e or %2e%2e segments to access protected resources within the WEB-INF directory. For example a request to /context/%2e/WEB-INF/web.xml can retrieve the web.xml file. This can reveal sensitive information regarding the implementation of a web application.

CVSS v3
5.3
EG Score
8.8HIGHhigh confidence
EG Risk
77
EG Risk 77/100CISA 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
Severity88% × 45%
Exploitation82% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track* or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
82%
EPSS %ILE
99th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* or Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (EG-KEV: weaponized) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). 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

April 1, 2021

Last Modified

November 21, 2024

References (50)

Vendor Advisories for CVE-2021-28164(6)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(6)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatjetty2022-09-09redhat
redhatpatch2021-11-23redhat
redhatpatch2021-09-30redhat
redhatjetty-server2021-08-19redhat
redhatpatch2021-05-13redhat
redhatrh-eclipse-jetty-0:9.4.40-1.1.el7_92021-05-06redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
jetty9—
  • every version up to 9.4.39-1: fixed in 9.4.39-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
jetty9—
  • every version up to 9.4.39-1: fixed in 9.4.39-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
jetty9—
  • every version up to 9.4.39-1: fixed in 9.4.39-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
jetty9—
  • every version up to 9.4.39-1: fixed in 9.4.39-1
—
Maven(1)
PackageVulnerable rangeFix by version rangeDependents
org.eclipse.jetty:jetty-webapp9.4.37.v20210219, 9.4.38.v20210224
  • 9.4.37 up to 9.4.39: fixed in 9.4.39
—

Weakness Classification(2)

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

Additional Vendor Advisories

(2)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 3× in last 7d / 11× 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. 2026-10-09 20:04 UTCEPSS rescore
  2. 2026-10-06 15:14 UTCEPSS rescore
  3. 2026-10-05 17:40 UTCEPSS rescore
  4. 2026-10-01 19:46 UTCEPSS rescore
  5. 2026-09-30 15:33 UTCEG score recompute
  6. 2026-09-26 05:25 UTCOSV refresh
  7. 2026-09-24 14:00 UTCEPSS rescore
  8. 2026-09-21 20:28 UTCEPSS rescore
  9. 2026-09-18 19:23 UTCEPSS rescore
  10. 2026-09-16 14:05 UTCEPSS rescore
  11. 2026-09-12 14:57 UTCEPSS rescore
  12. 2026-09-08 21:56 UTCEPSS rescore
  13. 2026-09-07 15:58 UTCEPSS rescore
  14. 2026-09-06 20:13 UTCOSV refresh
  15. 2026-09-06 13:44 UTCEPSS rescore
  16. 2026-09-05 15:25 UTCEPSS rescore
  17. 2026-09-04 13:57 UTCEPSS rescore
  18. 2026-09-02 14:08 UTCEPSS rescore
  19. 2026-08-30 19:14 UTCEPSS rescore
  20. 2026-08-28 21:37 UTCEPSS rescore
  21. 2026-08-26 14:42 UTCEPSS rescore
  22. 2026-08-25 13:45 UTCEPSS rescore
  23. 2026-08-24 14:12 UTCEPSS rescore
  24. 2026-08-21 23:46 UTCEPSS rescore
  25. 2026-08-20 06:15 UTCOSV refresh
Show 65 more
  1. 2026-08-19 17:01 UTCEPSS rescore
  2. 2026-08-16 02:11 UTCEPSS rescore
  3. 2026-08-16 02:11 UTCEPSS rescore
  4. 2026-08-15 01:27 UTCEPSS rescore
  5. 2026-08-12 13:47 UTCEPSS rescore
  6. 2026-08-09 13:43 UTCEPSS rescore
  7. 2026-08-08 16:33 UTCEPSS rescore
  8. 2026-08-07 16:23 UTCEPSS rescore
  9. 2026-08-05 01:11 UTCOSV refresh
  10. 2026-08-04 15:06 UTCEPSS rescore
  11. 2026-08-02 02:24 UTCEPSS rescore
  12. 2026-07-30 16:25 UTCEPSS rescore
  13. 2026-07-30 16:25 UTCEPSS rescore
  14. 2026-07-30 01:28 UTCEPSS rescore
  15. 2026-07-30 01:27 UTCEPSS rescore
  16. 2026-07-28 15:33 UTCEPSS rescore
  17. 2026-07-26 14:52 UTCEPSS rescore
  18. 2026-07-26 14:52 UTCEPSS rescore
  19. 2026-07-24 14:15 UTCEPSS rescore
  20. 2026-07-23 01:59 UTCEG score recompute▲ 3.50
  21. 2026-07-22 22:46 UTCEG score recompute▼ 3.70
  22. 2026-07-22 14:06 UTCEPSS rescore
  23. 2026-07-22 14:06 UTCEPSS rescore
  24. 2026-07-20 17:05 UTCEPSS rescore
  25. 2026-07-19 02:27 UTCEPSS rescore
  26. 2026-07-19 02:27 UTCEPSS rescore
  27. 2026-07-18 23:29 UTCOSV refresh
  28. 2026-07-15 16:55 UTCEPSS rescore
  29. 2026-07-15 16:55 UTCEPSS rescore
  30. 2026-07-13 22:27 UTCEPSS rescore
  31. 2026-07-13 22:27 UTCEPSS rescore
  32. 2026-07-11 08:25 UTCEPSS rescore
  33. 2026-07-11 08:25 UTCEPSS rescore
  34. 2026-07-08 15:12 UTCEPSS rescore
  35. 2026-07-04 06:29 UTCEPSS rescore
  36. 2026-07-04 06:29 UTCEPSS rescore
  37. 2026-07-01 15:03 UTCEPSS rescore
  38. 2026-07-01 06:18 UTCOSV refresh
  39. 2026-06-28 04:54 UTCEPSS rescore
  40. 2026-06-28 04:54 UTCEPSS rescore
  41. 2026-06-27 03:06 UTCEPSS rescore
  42. 2026-06-27 03:06 UTCEPSS rescore
  43. 2026-06-24 14:03 UTCEPSS rescore
  44. 2026-06-24 14:03 UTCEPSS rescore
  45. 2026-06-23 21:31 UTCEPSS rescore
  46. 2026-06-23 21:31 UTCEPSS rescore
  47. 2026-06-21 14:55 UTCEPSS rescore
  48. 2026-06-21 14:54 UTCEPSS rescore
  49. 2026-06-21 01:58 UTCEPSS rescore
  50. 2026-06-21 01:58 UTCEPSS rescore
  51. 2026-06-17 17:51 UTCEPSS rescore
  52. 2026-06-15 17:46 UTCEPSS rescore
  53. 2026-06-13 10:43 UTCOSV refresh
  54. 2026-06-12 23:10 UTCEPSS rescore
  55. 2026-06-05 22:45 UTCEPSS rescore
  56. 2026-06-05 22:45 UTCEPSS rescore
  57. 2026-06-02 20:11 UTCEPSS rescore
  58. 2026-06-02 20:11 UTCEPSS rescore
  59. 2026-06-02 20:11 UTCEPSS rescore
  60. 2026-05-31 22:29 UTCEPSS rescore
  61. 2026-05-31 22:29 UTCEPSS rescore
  62. 2026-05-29 13:42 UTCEPSS rescore
  63. 2026-05-26 18:56 UTCEG score recompute
  64. 2026-05-26 18:56 UTCVendor advisory
  65. 2026-05-26 13:42 UTCEPSS rescore

Publicly available exploits

(3 references)

Working exploit code is in the public domain (1 Metasploit module) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Metasploitauxiliary/gather/jetty_web_inf_disclosure✓ verified
    First seen Jul 15, 2021

    Jetty WEB-INF File Disclosure

    Open source ↗
  • Exploit-DBEDB-50438
    First seen Oct 22, 2021

    Jetty 9.4.37.v20210219 - Information Disclosure

    Open source ↗
  • Nucleihttp/cves/2021/CVE-2021-28164.yaml
    First seen Jan 1, 2021

    Eclipse Jetty - Information Disclosure

    Open source ↗

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2021-28164?
CVE-2021-28164 is a high vulnerability published on April 1, 2021. In Eclipse Jetty 9.4.37.v20210219 to 9.4.38.v20210224, the default compliance mode allows requests with URIs that contain %2e or %2e%2e segments to access protected resources within the WEB-INF directory. For example a request to /context/%2e/WEB-INF/web.xml can retrieve the web.xml file. This can…
When was CVE-2021-28164 disclosed?
CVE-2021-28164 was first published on April 1, 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-2021-28164 actively exploited?
CVE-2021-28164 is not currently on CISA's Known Exploited Vulnerabilities catalog. EchelonGraph's EG-KEV model classifies it as weaponized: a functional public exploit exists. FIRST EPSS estimates a 82% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-28164?
CVE-2021-28164 has a CVSS v3 base score of 5.3 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.8 (HIGH).
How do I remediate CVE-2021-28164?
A fix for CVE-2021-28164 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2021-28164 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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