Security readout for executives and security teams
Plain-English summary
CVE-2021-1577 is a critical Cisco APIC and Cloud APIC flaw where an unauthenticated remote attacker could read or write files on an affected system through an API endpoint. For executives, the business risk is unauthorized access to infrastructure controller files, with high confidentiality and integrity impact.
Executive priority
Treat this as urgent for environments running Cisco APIC or Cloud APIC, especially if management interfaces are broadly reachable. The issue has critical severity and unauthenticated remote access requirements, but exploitation evidence is not confirmed in the provided sources.
Technical view
The vulnerability is improper access control in an API endpoint of Cisco APIC and Cloud APIC. The CVSS 3.1 score is 9.1, with network access, low complexity, no privileges, and no user interaction required. Successful exploitation can read or write arbitrary files, but availability impact is not rated high.
Likely exposure
Exposure is most relevant where Cisco APIC or Cloud APIC management/API interfaces are reachable from untrusted networks. The source bundle does not provide affected version ranges, so teams must verify applicability against Cisco’s advisory and their deployed controller versions.
Exploitation context
The bundle does not state active exploitation, and CISA KEV status is false. The described attack path is remote and unauthenticated, making exposed management APIs high risk, but no public exploit status is established by the provided sources.
Researcher notes
Evidence is limited to the CVE record, CVE List data, and Cisco advisory reference. The bundle does not include affected version ranges, endpoint identifiers, proof-of-concept details, or confirmed exploit activity. Avoid assuming products or fixes beyond Cisco’s published advisory.
Mitigation direction
- Review Cisco’s advisory for affected releases, fixed software, and official workarounds.
- Inventory Cisco APIC and Cloud APIC deployments, including management API exposure.
- Reduce unnecessary external or untrusted access to APIC management interfaces.
- Prioritize vendor remediation for any confirmed affected deployments.
Validation and detection
- Confirm whether deployed APIC or Cloud APIC versions match Cisco advisory applicability.
- Check that management/API interfaces are not reachable from untrusted networks.
- Review relevant controller and API logs for unusual unauthenticated access patterns.
- Document remediation status and any Cisco guidance applied per environment.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-1577 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N3.95.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20210825 Cisco Application Policy Infrastructure Controller Arbitrary File Read and Write VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.