Security readout for executives and security teams
Plain-English summary
Cisco Packet Tracer for Windows has a local DLL injection flaw. An attacker who already has valid Windows credentials could place a crafted configuration file so Packet Tracer loads a malicious DLL when another user starts it, potentially running code as that user.
Executive priority
Treat this as a high-priority endpoint hygiene issue for environments using Packet Tracer on shared Windows systems. It is not internet-exposed, but it can enable privilege misuse between local users.
Technical view
CVE-2021-1593 is a CWE-427 path handling issue in Cisco Packet Tracer for Windows. The CVSS 3.1 score is 7.3 with local attack vector, low complexity, low privileges, and required user interaction. Successful exploitation can impact confidentiality, integrity, and availability under another user account.
Likely exposure
Exposure is limited to Windows systems running Cisco Packet Tracer, especially shared lab, training, or classroom machines where multiple users log in. The source bundle does not identify exact affected versions.
Exploitation context
The attacker must be local, authenticated, and able to influence a specific runtime path before Packet Tracer starts. The bundle does not indicate known active exploitation, and it is not listed as CISA KEV.
Researcher notes
Evidence supports a local authenticated DLL search/path handling weakness, not remote compromise. Version and fix details are incomplete in the provided bundle, so validation should anchor on Cisco's advisory rather than assumptions.
Mitigation direction
- Check Cisco's advisory for affected versions, fixed releases, or official workarounds.
- Remove Packet Tracer from systems where it is not required.
- Restrict local access to shared Windows systems running Packet Tracer.
- Use least-privilege accounts on training and lab workstations.
- Monitor for suspicious DLL loading related to Packet Tracer startup.
Validation and detection
- Inventory Windows endpoints for Cisco Packet Tracer installations.
- Compare installed versions with Cisco advisory guidance.
- Identify shared systems where multiple users run Packet Tracer.
- Review endpoint telemetry for unexpected DLL loads during Packet Tracer startup.
- Confirm local user permissions do not allow unnecessary path manipulation.
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-427: 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 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-2021-1593 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
- 7.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/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:R/S:U/C:H/I:H/A:H1.35.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.3HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20210804 Cisco Packet Tracer for Windows DLL Injection 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 Search Path Element
Uncontrolled Search Path Element represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
