CVE-2017-3203

HIGHNVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2022-05-13. NVD baseline CVSS 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 6.3%CVSS: 8.1Exploit: None knownExposed services: Not assessed

A fixed version is listed under Patch Availability — apply it.

The Java implementations of AMF3 deserializers in Pivotal/Spring Spring-flex derive class instances from java.io.Externalizable rather than the AMF3 specification's recommendation of flash.utils.IExternalizable. A remote attacker with the ability to spoof or control an RMI server connection may be able to send serialized Java objects that execute arbitrary code when deserialized.

CVSS v3
8.1
EG Score
8.1HIGHmedium confidence
EG Risk
43
EG Risk 43/100CISA 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
Severity81% × 45%
Exploitation6% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: A fixed version is listed under Patch Availability. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
6.3%
EPSS %ILE
93rd
KEV
Not listed

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

A fixed version is listed under Patch Availability. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · 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

June 11, 2018

Last Modified

November 21, 2024

Advisory Details (4)

Auto-updated Sep 16, 2026
🔬 Proof of concept available. Fixed version listed under Patch Availability. Sources: cert.
generic

CVE-2017-3203 - PSIRT.COM

https://www.securityfocus.com/bid/97376
cert

VU#307983 - Action Message Format (AMF3) Java implementations are vulnerable to insecure deserialization and XML external entities references

https://www.kb.cert.org/vuls/id/307983
generic🟡 PoC Available

CODE WHITE | Blog: AMF – Another Malicious Format

https://codewhitesec.blogspot.com/2017/04/amf.html
generic

Flaws in Java AMF Libraries Allow Remote Code Execution - SecurityWeek

http://www.securityweek.com/flaws-java-amf-libraries-allow-remote-code-execution

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
mavenorg.springframework.flex:spring-flex—ghsa

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

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFix by version rangeDependents
org.springframework.flex:spring-flex1.0.0.RELEASE ... 1.5.2.RELEASE (7 versions)
  • every version through 1.5.2.RELEASE: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 21× 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 135 total refreshes for this CVE.

  1. 2026-10-09 20:02 UTCEPSS rescore
  2. 2026-10-08 16:36 UTCEPSS rescore
  3. 2026-10-07 23:41 UTCEPSS rescore
  4. 2026-10-06 15:12 UTCEPSS rescore
  5. 2026-10-05 17:38 UTCEPSS rescore
  6. 2026-10-04 23:18 UTCEPSS rescore
  7. 2026-10-03 14:21 UTCEPSS rescore
  8. 2026-09-30 14:59 UTCEPSS rescore
  9. 2026-09-30 09:33 UTCEG score recompute
  10. 2026-09-28 13:45 UTCEPSS rescore
  11. 2026-09-27 13:40 UTCEPSS rescore
  12. 2026-09-27 13:40 UTCEPSS rescore
  13. 2026-09-26 15:53 UTCEPSS rescore
  14. 2026-09-24 13:59 UTCEPSS rescore
  15. 2026-09-18 19:22 UTCEPSS rescore
  16. 2026-09-17 19:22 UTCEPSS rescore
  17. 2026-09-15 03:05 UTCEPSS rescore
  18. 2026-09-15 03:05 UTCEPSS rescore
  19. 2026-09-13 16:42 UTCEPSS rescore
  20. 2026-09-12 14:55 UTCEPSS rescore
  21. 2026-09-11 09:31 UTCEPSS rescore
  22. 2026-09-07 15:56 UTCEPSS rescore
  23. 2026-09-06 13:43 UTCEPSS rescore
  24. 2026-09-05 15:23 UTCEPSS rescore
  25. 2026-09-04 13:56 UTCEPSS rescore
Show 75 more
  1. 2026-09-02 14:07 UTCEPSS rescore
  2. 2026-09-02 14:07 UTCEPSS rescore
  3. 2026-09-01 03:31 UTCEPSS rescore
  4. 2026-08-30 19:13 UTCEPSS rescore
  5. 2026-08-27 14:21 UTCEPSS rescore
  6. 2026-08-26 14:41 UTCEPSS rescore
  7. 2026-08-25 13:44 UTCEPSS rescore
  8. 2026-08-21 23:44 UTCEPSS rescore
  9. 2026-08-20 22:51 UTCEPSS rescore
  10. 2026-08-19 16:59 UTCEPSS rescore
  11. 2026-08-18 13:43 UTCEPSS rescore
  12. 2026-08-17 13:42 UTCEPSS rescore
  13. 2026-08-16 14:51 UTCEPSS rescore
  14. 2026-08-16 02:10 UTCEPSS rescore
  15. 2026-08-15 01:26 UTCEPSS rescore
  16. 2026-08-12 13:46 UTCEPSS rescore
  17. 2026-08-09 13:42 UTCEPSS rescore
  18. 2026-08-07 16:22 UTCEPSS rescore
  19. 2026-08-06 13:42 UTCEPSS rescore
  20. 2026-08-05 19:12 UTCEPSS rescore
  21. 2026-08-04 15:05 UTCEPSS rescore
  22. 2026-08-02 02:23 UTCEPSS rescore
  23. 2026-08-01 04:11 UTCEPSS rescore
  24. 2026-07-30 16:24 UTCEPSS rescore
  25. 2026-07-30 01:26 UTCEPSS rescore
  26. 2026-07-28 15:32 UTCEPSS rescore
  27. 2026-07-23 14:15 UTCEPSS rescore
  28. 2026-07-23 01:29 UTCEG score recompute
  29. 2026-07-22 22:08 UTCEG score recompute
  30. 2026-07-22 14:04 UTCEPSS rescore
  31. 2026-07-22 14:04 UTCEPSS rescore
  32. 2026-07-21 15:21 UTCEPSS rescore
  33. 2026-07-21 15:21 UTCEPSS rescore
  34. 2026-07-20 17:04 UTCEPSS rescore
  35. 2026-07-19 14:28 UTCEPSS rescore
  36. 2026-07-19 14:28 UTCEPSS rescore
  37. 2026-07-19 02:26 UTCEPSS rescore
  38. 2026-07-19 02:26 UTCEPSS rescore
  39. 2026-07-18 10:00 UTCEPSS rescore
  40. 2026-07-16 16:59 UTCEPSS rescore
  41. 2026-07-16 16:59 UTCEPSS rescore
  42. 2026-07-15 16:54 UTCEPSS rescore
  43. 2026-07-15 01:56 UTCEPSS rescore
  44. 2026-07-15 01:56 UTCEPSS rescore
  45. 2026-07-13 22:26 UTCEPSS rescore
  46. 2026-07-12 05:43 UTCEPSS rescore
  47. 2026-07-11 08:24 UTCEPSS rescore
  48. 2026-07-09 19:06 UTCEPSS rescore
  49. 2026-07-08 15:10 UTCEPSS rescore
  50. 2026-07-07 13:42 UTCEPSS rescore
  51. 2026-07-06 16:24 UTCEPSS rescore
  52. 2026-07-06 16:24 UTCEPSS rescore
  53. 2026-07-06 02:20 UTCEPSS rescore
  54. 2026-07-06 02:20 UTCEPSS rescore
  55. 2026-07-05 02:27 UTCEPSS rescore
  56. 2026-07-04 06:28 UTCEPSS rescore
  57. 2026-07-02 16:54 UTCEPSS rescore
  58. 2026-07-01 15:02 UTCEPSS rescore
  59. 2026-06-30 23:19 UTCEPSS rescore
  60. 2026-06-30 23:19 UTCEPSS rescore
  61. 2026-06-29 14:03 UTCEPSS rescore
  62. 2026-06-28 04:53 UTCEPSS rescore
  63. 2026-06-27 03:06 UTCEPSS rescore
  64. 2026-06-27 03:05 UTCEPSS rescore
  65. 2026-06-25 13:47 UTCEPSS rescore
  66. 2026-06-24 14:02 UTCEPSS rescore
  67. 2026-06-24 14:02 UTCEPSS rescore
  68. 2026-06-23 21:30 UTCEPSS rescore
  69. 2026-06-22 14:23 UTCEPSS rescore
  70. 2026-06-22 14:23 UTCEPSS rescore
  71. 2026-06-21 14:54 UTCEPSS rescore
  72. 2026-06-21 14:54 UTCEPSS rescore
  73. 2026-06-19 19:23 UTCEPSS rescore
  74. 2026-06-19 19:23 UTCEPSS rescore
  75. 2026-06-18 17:50 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2017-3203?
CVE-2017-3203 is a high vulnerability published on June 11, 2018. The Java implementations of AMF3 deserializers in Pivotal/Spring Spring-flex derive class instances from java.io.Externalizable rather than the AMF3 specification's recommendation of flash.utils.IExternalizable. A remote attacker with the ability to spoof or control an RMI server connection may be…
When was CVE-2017-3203 disclosed?
CVE-2017-3203 was first published on June 11, 2018, 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-2017-3203 actively exploited?
CVE-2017-3203 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 6.3% probability of exploitation in the next 30 days (93rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2017-3203?
CVE-2017-3203 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2017-3203?
A fixed version for CVE-2017-3203 is listed under Patch Availability on this page: update to the version listed for your package.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2017-3203

Explore →

Is Your Infrastructure Affected by CVE-2017-3203?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs