Security readout for executives and security teams
Plain-English summary
This flaw can expose passwords configured through Cisco security appliance management screens to a logged-in remote user. It is not described as unauthenticated or actively exploited, but password exposure can undermine gateway administration and downstream security controls.
Executive priority
Treat this as a moderate-priority credential exposure issue. It is lower urgency than remote code execution, but appliances handling email and web security are high-value control points, so remediation should be scheduled promptly.
Technical view
Cisco AsyncOS web management requests may include confidential information. An authenticated remote attacker with interface access could view raw HTTP request data and obtain some passwords configured through the interface. CVSS 3.1 is 4.3, reflecting low confidentiality impact and no integrity or availability impact.
Likely exposure
Review Cisco Content Security Management Appliance, Email Security Appliance, and Web Security Appliance environments using the web-based management interface. The provided affected-product entry explicitly lists Cisco WSA; the CVE description also names SMA and ESA.
Exploitation context
The source states exploitation requires authenticated remote access to the management interface. CISA KEV status is false in the bundle, and no cited source states active exploitation. Evidence provided does not include public exploit status.
Researcher notes
The bundle does not provide affected version ranges, fixed releases, or workaround specifics. Avoid inferring products beyond the source description and affected entry. The key condition is authenticated management access plus sensitive values appearing in web-management HTTP requests.
Mitigation direction
- Check Cisco's advisory for affected and fixed AsyncOS releases.
- Restrict management-interface access to trusted administrators and networks.
- Review privileged appliance accounts for least-privilege access.
- Rotate exposed or potentially exposed configured passwords after remediation.
- Monitor vendor guidance for any updated workaround or fix details.
Validation and detection
- Inventory Cisco WSA, ESA, and SMA appliances and AsyncOS versions.
- Compare deployed versions with Cisco advisory affected-release guidance.
- Confirm management interfaces are not broadly reachable.
- Review administrative access logs for unusual authenticated management activity.
- Verify password rotation occurred where exposure cannot be ruled out.
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-540: 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-2021-1516 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
- 4.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/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:L/UI:N/S:U/C:L/I:N/A:N2.81.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20210505 Cisco Content Security Management Appliance, Email Security Appliance, and Web Security Appliance Information Disclosure 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.
Inclusion of Sensitive Information in Source Code
Inclusion of Sensitive Information in Source Code represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.