CVE-2020-3139

Cisco Application Policy Infrastructure Controller Out Of Band Management IP Tables Bypass Vulnerability

MEDIUM
5.3
CVSS Score
Published: January 26, 2020 at 04:30 AM UTC
Updated: June 17, 2026 at 03:17 AM UTC
1 product affected across 1 vendorApplication Policy Infrastructure Controller

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Severity
MEDIUM5.3
Exploit prediction
EPSS 1%
SSVC
No known exploit

Description

A vulnerability in the out of band (OOB) management interface IP table rule programming for Cisco Application Policy Infrastructure Controller (APIC) could allow an unauthenticated, remote attacker to bypass configured deny entries for specific IP ports. These IP ports would be permitted to the OOB management interface when, in fact, the packets should be dropped. The vulnerability is due to the configuration of specific IP table entries for which there is a programming logic error that results in the IP port being permitted. An attacker could exploit this vulnerability by sending traffic to the OOB management interface on the targeted device. A successful exploit could allow the attacker to bypass configured IP table rules to drop specific IP port traffic. The attacker has no control over the configuration of the device itself. This vulnerability affects Cisco APIC releases prior to the first fixed software Release 4.2(3j).

Affected

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

v < 4.2v < 4.2(3j)
Affected range stops below 4.2, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.2(3j), 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
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-20

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