dbcve.org
Packet TracerApplication · Cisco

CVE-2021-1593

HIGH · 7.3 CVSS v3.1 Published 2021-08-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
73/100
Remediation priority · Elevated

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability in Cisco Packet Tracer for Windows could allow an authenticated, local attacker to perform a DLL injection attack on an affected device. To exploit this vulnerability, the attacker must have valid credentials on the Windows system. This vulnerability is due to incorrect handling of directory paths at run time. An attacker could exploit this vulnerability by inserting a configuration file in a specific path on the system, which can cause a malicious DLL file to be loaded when the application starts. A successful exploit could allow an attacker with normal user privileges to execute arbitrary code on the affected system with the privileges of another user’s account.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a DLL injection vulnerability in Cisco Packet Tracer for Windows where an authenticated local attacker with valid Windows credentials can place a malicious configuration file in a specific directory path. When Packet Tracer starts, it incorrectly handles the directory path and loads a malicious DLL from this location, allowing the attacker to execute arbitrary code with the privileges of another user account.

MitigationApply the vendor patch from Cisco when available. In the interim, ensure untrusted users do not have write access to directories in the application's DLL search path, and restrict who has physical or logical access to the Windows system running Packet Tracer.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Packet TracerApplication
Affected:= 7.2.0= 7.2.1= 7.2.2= 7.3.0= 7.3.1= 8.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify Cisco Packet Tracer is installed
    Open Windows Programs and Features or check common installation directories such as C:\Program Files\Cisco Packet Tracer or C:\Program Files (x86)\Cisco Packet Tracer for the presence of Cisco Packet Tracer
    Affected if The software is not installed on the Windows system
  2. Identify installed Packet Tracer version
    Right-click the Packet Tracer executable (usually PacketTracer.exe), select Properties, and view the File version on the Details tab. Alternatively, open the application and check Help > About Cisco Packet Tracer
    Affected if The installed version is 7.2.0, 7.2.1, 7.2.2, 7.3.0, 7.3.1, or 8.0
  3. Review DLL search path directories for write permissions
    Use icacls or Right-click > Properties > Security on directories where Packet Tracer is installed and its configuration files are stored. Check which users or groups have Write or Create permissions
    Affected if Untrusted or low-privilege users have Write access to any directory in Packet Tracer's DLL search or configuration load path
  4. Check for malicious configuration files
    Inspect the Packet Tracer application directory and any subdirectories for unexpected .dll or .ini configuration files that were not created by the installation or legitimate users
    Affected if Unexpected DLL or config files exist in directories that Packet Tracer reads from on startup
  5. Verify user account isolation
    Review which Windows user accounts have physical or console access to the system, and check if multiple users share accounts or have concurrent login capabilities
    Affected if Multiple users have authenticated access to the same Windows system running Packet Tracer

You are affected if Cisco Packet Tracer versions 7.2.0 through 8.0 are installed and untrusted users have write access to directories in the application's DLL search path.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor patch from Cisco when available. In the interim, ensure untrusted users do not have write access to directories in the application's DLL search path, and restrict who has physical or logical access to the Windows system running Packet Tracer.

Fix this in Packet Tracer Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-1593 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data