Security readout for executives and security teams
Plain-English summary
This flaw can let an unauthenticated remote attacker overload affected Cisco ASA or FTD devices by creating many connections. A successful attack can force the device to reload, interrupting firewall or security-service availability.
Executive priority
Prioritize remediation for exposed perimeter firewalls because impact is outage-driven. The business risk is service disruption, failed security enforcement, and incident-response load rather than confidentiality loss.
Technical view
Cisco describes improper resource management in ASA and FTD memory handling during high connection rates. The CVSS 3.1 score is 8.6, network exploitable, low complexity, no privileges, no user interaction, with high availability impact only.
Likely exposure
Exposure is most relevant for organizations running Cisco ASA Software or Firepower Threat Defense Software where attackers can initiate many network connections to the device. The provided bundle does not list exact affected or fixed versions.
Exploitation context
The source bundle supports unauthenticated remote denial of service, but not data theft or code execution. CISA KEV is false, and no provided source states active exploitation in the wild.
Researcher notes
This is CWE-400 resource exhaustion. The key validation question is version and exposure, not exploit sophistication. The provided evidence does not include fixed-release details, exploit proof, or observed exploitation.
Mitigation direction
- Review Cisco advisory for affected and fixed ASA/FTD releases.
- Apply Cisco-recommended software updates or workarounds where applicable.
- Prioritize perimeter or internet-reachable ASA/FTD devices.
- Treat compensating controls as risk reduction, not a confirmed fix.
Validation and detection
- Inventory Cisco ASA and FTD devices and software versions.
- Compare versions against Cisco advisory CVE-2021-34792.
- Check for unexpected device reloads during high connection-rate periods.
- Review whether untrusted networks can reach affected device interfaces.
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-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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 lookupCVE-2021-34792 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
- High
- CVSS
- 8.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
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:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.6HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20211027 Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Resource Exhaustion Denial of Service 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.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.