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CVE Record

CVE-2018-3840: A denial-of-service vulnerability exists in the Pixar Renderman IT Display Service 21.6 (0x67).

A denial-of-service vulnerability exists in the Pixar Renderman IT Display Service 21.6 (0x67). The vulnerability is present in the parsing of a network packet without proper validation of the packet. The data read by the application is not validated, and its use can lead to a null pointer dereference. The IT application is opened by a user and then listens for a connection on port 4001. An attacker can deliver an attack once the application has been opened.

MediumCVSS 5.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2018-3840 can crash Pixar RenderMan’s IT Display Service 21.6 when it processes a malformed network packet. The business impact is availability only: disrupted rendering/display workflows, not data theft or system takeover based on the supplied sources.

Executive priority

Treat as a moderate operational risk for rendering environments. Prioritize remediation where RenderMan 21.6 supports production workflows or where port 4001 is reachable beyond trusted workstation networks.

Technical view

The flaw is in network packet parsing in IT Display Service 21.6. The application listens on port 4001 after a user opens it. Insufficient packet validation can lead to a null pointer dereference and denial of service. CVSS v3.0 is 5.3 with network attack vector and low complexity.

Likely exposure

Exposure is likely limited to environments using Pixar RenderMan 21.6 where the IT application is opened and port 4001 is reachable. Internet exposure would increase urgency, but the sources do not say this service is normally internet-facing.

Exploitation context

The source bundle does not indicate active exploitation, and the CVE is not listed as KEV. The described attack is unauthenticated over the network once the application is listening, but the documented impact is limited to service crash or availability loss.

Researcher notes

Evidence supports a packet-validation null pointer dereference in IT Display Service 21.6. The supplied sources do not name a fixed version, vendor workaround, public exploit, or exploitation in the wild. Avoid expanding affected versions beyond 21.6.

Mitigation direction

  • Check Pixar or RenderMan guidance for fixed versions or vendor workarounds.
  • Restrict network access to port 4001 to trusted hosts only.
  • Avoid exposing IT Display Service to untrusted or internet-facing networks.
  • Prioritize upgrade or isolation for active RenderMan 21.6 production systems.

Validation and detection

  • Inventory systems running Pixar RenderMan 21.6.
  • Confirm whether users run the IT Display Service application.
  • Check whether port 4001 is reachable from untrusted networks.
  • Review crash reports for IT Display Service null pointer failures.
  • Verify vendor guidance before claiming a patched state.
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.

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CVE-2018-3840 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.3 (3.0)
Known Exploited
No
Published

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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
5.3CVSS 3.0MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L3.91.4Primary CVE score

Vulnerability scoring details

Base CVSS 3.0 score

5.3Medium
CVSS 3.0 vector shape for CVE-2018-3840Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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
TalosPixar RendermanRenderman 21.6Listed
Weakness

CWE details

No CWE listed

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