CVE-2019-12655

Cisco IOS XE Software FTP Application Layer Gateway for NAT, NAT64, and ZBFW Denial of Service Vulnerability

HIGH
7.5
CVSS Score
Published: September 25, 2019 at 08:15 PM UTC
Updated: June 17, 2026 at 02:15 AM UTC
1 product affected across 1 vendorIOS

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Severity
HIGH7.5
Exploit prediction
EPSS 2%
SSVC
No known exploit

Description

A vulnerability in the FTP application layer gateway (ALG) functionality used by Network Address Translation (NAT), NAT IPv6 to IPv4 (NAT64), and the Zone-Based Policy Firewall (ZBFW) in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to a buffer overflow that occurs when an affected device inspects certain FTP traffic. An attacker could exploit this vulnerability by performing a specific FTP transfer through the device. A successful exploit could allow the attacker to cause the device to reload.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

16.10.1 ≤ v < 16.11.13.16.8s ≤ v < 16.3.816.6.416.6.516.9.116.9.2
Affected range stops below 16.11.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 16.3.8, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-20CWE-120

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