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CVE-2021-1577

29
FAUCET Score

CVE-2021-1577 is a critical vulnerability affecting Cisco Application Policy Infrastructure Controller (APIC) and Cloud APIC, allowing unauthenticated, remote attackers to read or write arbitrary files due to improper access control via a specific API endpoint. With a CVSS score of 9.1 (CRITICAL), this vulnerability presents a high risk as it can be exploited remotely with low complexity, leading to complete compromise of file integrity and confidentiality. While there is no evidence of active exploitation or public exploit code (Metasploit, Nuclei, ExploitDB), the vulnerability has garnered significant community discussion and media coverage, indicating awareness and potential for future exploitation.

Impacted Technologies

VendorProductVersion(s)CPE
< 3.2\(10e\)CPE matchmatch criteria
cpe:2.3:a:cisco:application_policy_infrastructure_controller:*:*:*:*:*:*:*:*
>= 4.0, < 4.2\(6h\)CPE matchmatch criteria
cpe:2.3:a:cisco:application_policy_infrastructure_controller:*:*:*:*:*:*:*:*
>= 5.0, < 5.1\(3e\)CPE matchmatch criteria
cpe:2.3:a:cisco:application_policy_infrastructure_controller:*:*:*:*:*:*:*:*
< 3.2\(10e\)CPE matchmatch criteria
cpe:2.3:a:cisco:cloud_application_policy_infrastructure_controller:*:*:*:*:*:*:*:*
>= 4.0, < 4.2\(6h\)CPE matchmatch criteria
cpe:2.3:a:cisco:cloud_application_policy_infrastructure_controller:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

9.1CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
Exploitability Score
3.9
Impact Score
5.2
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.30%
Probability of exploitation in next 30 days
EPSS Percentile
67.5%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0130 is in the 54th percentile among its peer group of 36,835 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Vendor Patches (1)

ciscovendor investigatingvia nvd_reference
View patch

References

tools.cisco.com / security/center/content/CiscoSecurityAdvisory/cisco-sa-capic-frw-Nt3RYxR2
Vendor Advisory