Security readout for executives and security teams
Plain-English summary
CVE-2021-1568 can let a signed-in local Windows user crash Cisco AnyConnect's VPN Agent service on a shared system. The main business impact is loss of VPN availability for users on that machine, not data theft or remote takeover.
Executive priority
Treat this as a moderate availability risk. It is unlikely to justify emergency response by itself, but shared Windows hosts using AnyConnect should be checked and updated through normal vulnerability management.
Technical view
Cisco describes an uncontrolled memory allocation issue in AnyConnect Secure Mobility Client for Windows. A low-privileged authenticated local attacker on a multiuser Windows system can trigger a VPN Agent service crash when the affected application launches. CVSS 3.1 is 5.5, with high availability impact only.
Likely exposure
Exposure is most relevant on Windows endpoints or shared Windows environments running Cisco AnyConnect Secure Mobility Client, especially where multiple users can sign in locally. The provided sources do not identify specific affected versions in the bundle.
Exploitation context
The source bundle says exploitation requires valid credentials on a multiuser Windows system and local access. CISA KEV is false, and the provided sources do not state active exploitation or public weaponization.
Researcher notes
Evidence supports local authenticated denial of service only. The bundle does not provide affected version ranges, patch version details, or exploitation-in-the-wild evidence. Avoid assuming broader Cisco VPN products or non-Windows platforms are affected.
Mitigation direction
- Review Cisco's advisory for affected and fixed release guidance.
- Apply Cisco-recommended updates when your installed version is confirmed affected.
- Prioritize shared Windows hosts where AnyConnect is installed.
- Limit unnecessary local access on multiuser Windows systems.
- Monitor for VPN Agent service crashes on managed endpoints.
Validation and detection
- Inventory Windows systems running Cisco AnyConnect Secure Mobility Client.
- Compare installed versions with Cisco's advisory guidance.
- Identify shared or multiuser Windows systems with AnyConnect installed.
- Review endpoint logs for recurring VPN Agent service crashes.
- Confirm whether compensating access controls limit local authenticated users.
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
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Open ATT&CK lookupCVE-2021-1568 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
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20210616 Cisco AnyConnect Secure Mobility Client for Windows 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.
Memory Allocation with Excessive Size Value
Memory Allocation with Excessive Size Value represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.