Security readout for executives and security teams
Plain-English summary
Certain Cisco ASA and FTD devices may answer SNMPv3 queries from hosts that should be blocked by configured access controls. An attacker still needs valid SNMPv3 credentials, but the flaw can expose device information despite source restrictions.
Executive priority
Treat this as a moderate network-management exposure issue. Prioritize internet- or broadly reachable firewall management planes, then apply Cisco guidance during normal security maintenance windows unless exposure is high.
Technical view
CVE-2021-34794 is an SNMPv3 access control weakness in Cisco ASA Software and Cisco FTD Software. Ineffective ACL enforcement may let a remote attacker with valid SNMPv3 credentials query an affected device from an unauthorized host and retrieve SNMP information.
Likely exposure
Exposure is most relevant where ASA or FTD devices run SNMPv3 and rely on SNMP ACLs to restrict which management hosts can query them.
Exploitation context
The source bundle does not identify public exploitation, and the CVE is not marked KEV. Exploitation requires network reachability to SNMPv3 and valid SNMP credentials, according to the CVE description.
Researcher notes
The key nuance is credentials: the attacker is described as unauthenticated remotely, but valid SNMPv3 credentials are required for the query. Evidence here does not include fixed-version details or exploitation reports.
Mitigation direction
- Review the Cisco advisory for affected ASA and FTD releases.
- Apply Cisco-recommended fixed software if your release is affected.
- Reduce SNMP exposure to approved management networks using existing controls.
- Disable SNMP where it is not operationally required.
- Review SNMPv3 credentials and rotate any overbroad or stale accounts.
Validation and detection
- Inventory Cisco ASA and FTD devices running SNMPv3.
- Confirm whether SNMP ACLs are used for source restrictions.
- Check device software versions against Cisco's advisory.
- Validate SNMP is reachable only from intended management paths.
- Review logs for unexpected SNMP queries from unauthorized hosts.
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 lookupCVE-2021-34794 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
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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:N/I:L/A:N3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20211027 Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software SNMP Access Control 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.