CVE-2017-12231

HIGHNVD 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
7.5
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 7%CVSS: 7.5Exploit: NoneExposed: 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)
EPSS
93.3%
KEV
⚠ Exploited

Published

September 29, 2017

Last Modified

April 21, 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

Data Freshness Timeline

(refreshed 92× in last 7d / 399× 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 538 total refreshes for this CVE.

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

Frequently asked(6)

What is CVE-2017-12231?
CVE-2017-12231 is a high 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 April 21, 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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