Skip to content
Fencer Vulns
high 7.5

CVE-2017-12231 kev in the critical feed json

A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS 12.4 through 15.6 could allow an unau…

published 2017-09-28 9 y ago modified 2026-06-17 4 mo ago also EUVD-2017-3804

cvss
7.5
version 3.1, CNA
cisa kev
Exploited
added 2022-03-03
epss
7.1%
EPSS 7.1% chance of exploitation in 30 days, percentile 94%
public exploits
0
none known

Summary

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.

Patch / fix

cisa required action Apply updates per vendor instructions.

Timeline

  1. Published
  2. Added to CISA KEV
  3. CISA patch deadline
  4. CISA SSVC: exploitation active

Known exploited

Added
4 y ago
Patch by
2022-03-24 (4 y ago)
Ransomware
Not known
Required action
Apply updates per vendor instructions.
Vendor, product
Cisco, IOS software
CISA name
Cisco IOS Software Network Address Translation Denial-of-Service Vulnerability

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

7.07% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 7.8 AV:N/AC:L/Au:N/C:N/I:N/A:C

Affected products

  • n/a Cisco IOS

Classification

Weakness
  • CWE-399 Resource Management Errors
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.