CVE-2017-12231

CRITICALNVD 7.59.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2022-03-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 7.5 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 4 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 7%CVSS: 7.5Exploit: cisa kev · ssvc activeExposed: 0

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

A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS 12.4 through 15.6 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to the improper translation of H.323 messages that use the Registration, Admission, and Status (RAS) protocol and are sent to an affected device via IPv4 packets. An attacker could exploit this vulnerability by sending a crafted H.323 RAS packet through an affected device. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition. This vulnerability affects Cisco devices that are configured to use an application layer gateway with NAT (NAT ALG) for H.323 RAS messages. By default, a NAT ALG is enabled for H.323 RAS messages. Cisco Bug IDs: CSCvc57217.

CVSS v3
7.5
EG Score
9.0(high)
EG Risk
96(Attend)
EG Risk 96/100SSVC: Attend

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
Severity90% × 45%
Exploitation100% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
7%
EPSS %ILE
94%
KEV
⚠ Exploited

Published

September 29, 2017

Last Modified

June 17, 2026

Advisory Details (4)

Auto-updated May 19, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-12231
generic🔴 Active Exploitation

Cisco IOS Software Network Address Translation Denial of Service Vulnerability

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170927-nat
generic
http://www.securitytracker.com/id/1039449
generic
http://www.securityfocus.com/bid/101039

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 41× in last 7d / 222× 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 462 total refreshes for this CVE.

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

Frequently asked(6)

What is CVE-2017-12231?
CVE-2017-12231 is a critical vulnerability published on September 29, 2017. A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS 12.4 through 15.6 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to the improper translation of H.323…
When was CVE-2017-12231 disclosed?
CVE-2017-12231 was first published in the National Vulnerability Database on September 29, 2017, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2017-12231 actively exploited?
Yes. CISA added CVE-2017-12231 to the Known Exploited Vulnerabilities catalog on March 3, 2022, affecting Cisco IOS software. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2017-12231?
CVE-2017-12231 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2017-12231?
CVE-2017-12231 affects Cisco IOS software. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2017-12231?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2017-12231, 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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