Security readout for executives and security teams
Plain-English summary
This is a Cisco FXOS flaw where someone who already has local administrative access could trigger a buffer overflow through a crafted file. The business risk is privilege escalation to root on affected security infrastructure, but the entry barrier is high because valid admin credentials are required.
Executive priority
Treat this as a targeted infrastructure hardening issue, not a broad internet worm risk. Prioritize systems where administrative access is shared, outsourced, or weakly logged because successful exploitation could give root control over affected security appliances.
Technical view
CVE-2020-3545 is a CWE-119 bounds-checking issue in Cisco FXOS file parsing. Processing a crafted file may cause a stack-based buffer overflow and allow arbitrary code execution on the underlying operating system as root. CVSS 3.1 is 6.0 with AV:L, PR:H, and no user interaction.
Likely exposure
Exposure is limited to Cisco Firepower Extensible Operating System deployments running affected software, especially where administrative accounts are broadly shared or insufficiently monitored. The source bundle does not include specific vulnerable or fixed version ranges.
Exploitation context
The CVE is not listed as CISA KEV in the provided bundle. Exploitation requires valid administrative credentials and local ability to supply a crafted file that FXOS later processes. No public exploitation evidence is provided in the bundle.
Researcher notes
Key unknowns are the affected release matrix, fixed releases, and any workaround details, which are not included in the source bundle text. Analysis should stay anchored to Cisco's advisory before asserting version exposure or remediation completeness.
Mitigation direction
- Review Cisco's advisory for affected and fixed FXOS releases.
- Upgrade or apply vendor-recommended remediation where applicable.
- Limit FXOS administrative access to trusted, named operators.
- Enforce MFA and strong credential controls for administrator accounts.
- Monitor administrative file changes and unusual local activity on FXOS devices.
Validation and detection
- Inventory all Cisco FXOS-managed appliances and recorded software versions.
- Compare installed versions against the Cisco advisory's affected release guidance.
- Review administrator account membership and recent credential changes.
- Check device logs for unusual administrative file operations or local command activity.
- Confirm remediation status after any FXOS update or vendor workaround.
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
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CWE-119: Exact CWE lookup
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Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-3545 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:H/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:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N0.85.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6MediumVector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20200902 Cisco FXOS Software Buffer Overflow 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 Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.