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CVE Record

CVE-2021-3042: Cortex XDR Agent: Improper Control of User-Controlled File Leads to Local Privilege Escalation

A local privilege escalation (PE) vulnerability exists in the Palo Alto Networks Cortex XDR agent on Windows platforms that enables an authenticated local Windows user to execute programs with SYSTEM privileges. Exploiting this vulnerability requires the user to have file creation privilege in the Windows root directory (such as C:\). This issue impacts: All versions of Cortex XDR agent 6.1 without content update 181 or a later version; All versions of Cortex XDR agent 7.2 without content update 181 or a later version; All versions of Cortex XDR agent 7.3 without content update 181 or a later version. Cortex XDR agent 5.0 versions are not impacted by this issue. Content updates are required to resolve this issue and are automatically applied for the agent.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2021-3042 lets a local Windows user turn limited access into SYSTEM-level control on affected Palo Alto Networks Cortex XDR agents. Business risk is highest on shared or user-accessible Windows endpoints where the required file-creation condition exists.

Executive priority

Treat this as a high-priority endpoint hygiene issue, not an internet-facing emergency. Confirm content update coverage across Windows endpoints and prioritize any lagging systems, especially shared workstations or servers with local user access.

Technical view

The issue is a Windows local privilege escalation in Cortex XDR Agent tied to improper control of a user-controlled file, mapped to CWE-427. An authenticated local user can execute programs with SYSTEM privileges if they can create files in the Windows root directory, such as C:\.

Likely exposure

Exposure is limited to Windows systems running Cortex XDR Agent 6.1, 7.2, or 7.3 without content update 181 or later. The source states Cortex XDR Agent 5.0 is not impacted. Systems already receiving content update 181 or later should be remediated.

Exploitation context

The source bundle does not show CISA KEV listing or other evidence of active exploitation. Exploitation requires authenticated local Windows access and file creation privilege in the Windows root directory, so this is most relevant after initial access or on shared endpoints.

Researcher notes

The key conditions are local authentication, Windows platform, affected Cortex XDR Agent version, and ability to create files in the Windows root directory. Evidence in the bundle is sufficient for exposure triage, but it does not provide exploit telemetry or detailed vendor internals.

Mitigation direction

  • Confirm affected agents have content update 181 or later.
  • Ensure Cortex XDR content updates are applying automatically.
  • Prioritize Windows agents on versions 6.1, 7.2, and 7.3.
  • For exceptions, follow Palo Alto Networks advisory guidance.
  • Do not treat Cortex XDR Agent 5.0 as affected based on the advisory text.

Validation and detection

  • Inventory Windows endpoints running Cortex XDR Agent.
  • Record each agent version and content update level.
  • Flag 6.1, 7.2, or 7.3 agents below content update 181.
  • Check whether local users can create files in C:\.
  • Review endpoint logs for suspicious SYSTEM process launches from local user context.
Prepared
Confidence
high
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · low confidence lookup

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.

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description · low confidence lookup

Privilege behavior lookup

The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2021-3042 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

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

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2021-3042Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Palo Alto NetworksCortex XDR Agent5.0 allListed
Palo Alto NetworksCortex XDR Agent6.1.* without content update 181 or later, 6.1.* with content update 181 or later, 7.2.* without content update 181 or laterListed
Palo Alto NetworksCortex XDR Agent7.2.* with content update 181 or later, 7.3.* with content update 181 or later, 7.3.* without content update 181 or laterListed
Weakness

CWE details

CWE-427

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-427 · source CWE mapping

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.

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