CVE-2021-1577: Cisco Application Policy Infrastructure Controller Arbitrary File Read and Write Vulnerability

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-08-25 · updated 2026-06-17
Weakness: CWE-284

Description

A vulnerability in an API endpoint of Cisco Application Policy Infrastructure Controller (APIC) and Cisco Cloud Application Policy Infrastructure Controller (Cloud APIC) could allow an unauthenticated, remote attacker to read or write arbitrary files on an affected system. This vulnerability is due to improper access control. An attacker could exploit this vulnerability by using a specific API endpoint to upload a file to an affected device. A successful exploit could allow the attacker to read or write arbitrary files on an affected device.

Affected products

Cisco Application Policy Infrastructure Controller (APIC): before 3.2\(10e\); from 4.0 before 4.2\(6h\); from 5.0 before 5.1\(3e\) — fixed in 3.2\(10e\), 4.2\(6h\), 5.1\(3e\)
Cisco Cloud Application Policy Infrastructure Controller: before 3.2\(10e\); from 4.0 before 4.2\(6h\); from 5.0 before 5.1\(3e\) — fixed in 3.2\(10e\), 4.2\(6h\), 5.1\(3e\)

How to fix

Upgrade to a fixed version: Cisco Application Policy Infrastructure Controller (APIC) 3.2\(10e\), 4.2\(6h\), 5.1\(3e\); Cisco Cloud Application Policy Infrastructure Controller 3.2\(10e\), 4.2\(6h\), 5.1\(3e\). Check the vendor advisory for mitigations.

References

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