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Fencer Vulns
medium 5.3

CVE-2020-3139 json

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

published 2020-01-26 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-24410

cvss
5.3
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 64%
public exploits
0
none known

Summary

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).

Patch / fix

  • cisco application_policy_infrastructure_controller 4.2\(3j\)

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
23 mo ago

Exploit prediction

1.04% chance of exploitation in the next 30 days, higher than 64% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.0 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Affected products

  • Cisco Cisco Application Policy Infrastructure Controller (APIC)

Classification

Weakness
  • CWE-20 Improper Input Validation

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.