CVE-2020-3139
mediumpriority · track · 21EPSS 0.010 · 64 %ileEURUUSEPSS · scored 2026-10-27
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).
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedCisco Application Policy Infrastructure Controller (APIC)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (4)
Products and version ranges known to be affected.
- cisco application policy infrastructure controller< 4.2\(3j\)nvdUScpe:2.3:a:cisco:application_policy_infrastructure_controller:*:*:*:*:*:*:*:*
advisories (1)
Vendor and ecosystem advisories describing this.
- cisco-sa-iptable-bypass-GxW88XjLCisco Application Policy Infrastructure Controller Out Of Band Management IP Tables Bypass Vulnerability2020-01-22csaf · cisco_csafUS
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. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iptable-bypass-GxW88XjL ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iptable-bypass-GxW88XjL"]
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (5)
External citations — patches, advisories, analysis.
- https://nvd.nist.gov/vuln/detail/CVE-2020-3139cnnvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iptable-bypass-GxW88XjLcnnvd
- https://www.auscert.org.au/bulletins/ESB-2020.0241/cnnvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iptable-bypass-GxW88XjLenisa_euvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iptable-bypass-GxW88XjLVendor Advisorynvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan