HOL LogoGuard

Explore HOL

  • HOL home
  • AI agent registry
  • AI plugins
  • Open standards
  • HOL members
  • Sponsor HOL
  • Advertise with HOL

Guard product

  • Guard overviewLocal security and control for AI agents and the tools they use.
  • FeaturesRuntime protection, policy routing, review, and evidence.

Explore Guard

  • Product previewWalk through Guard surfaces in read-only demo mode.
  • ComparisonCompare Guard with native controls and AI security vendors.

AI tools

  • All AI toolsEvery supported AI tool and how Guard applies policy to it.
  • Codex
  • Claude Code
  • Cursor
  • Antigravity CLI
  • OpenCode
  • Hermes
  • OpenClaw
  • GitHub Copilot CLI
  • Antigravity
  • Kimi
  • Grok
  • Pi / Oh My Pi
  • Zcode

Extensions

  • All extensionsBrowse command and MCP coverage with owners and stated limits.
  • Command coverageShell command protection across clouds, databases, backups, and packages.
  • MCP server coverageSee how Guard maps risk state across MCP tools and servers.
  • Core safetyThe safety floor listings that ship with Guard.
  • Data and resilienceBackup and storage command protection.
  • Cloud and infrastructureAWS, Azure, GCP, Kubernetes, and more.

Security

  • AI security hubSecurity research, advisories, and agent safety coverage.
  • AI tool securitySecurity profiles for each supported coding agent.
  • Safe labsHands-on attack simulations with safe boundaries.
  • Redacted warningsReal blocked actions with sensitive details removed.
  • AdvisoriesCoordinated disclosure reports for AI tooling.
  • Active CVEsSearch active CVEs affecting AI tooling.

Learn

  • Security guidesPractical guides for securing AI agent workflows.
  • DocsInstall, configure, and operate Guard with confidence.
  • ResearchPublished security research, benchmarks, and methodology.

Community

  • ReleasesVersion history, shipped changes and upgrade notes.
  • ContributorsThe people and contributions behind HOL Guard.
  • AffiliatesShare Guard with your audience and earn from referrals.
  • SponsorFund agreed research, implementation and shared testing through the HOL Partner Program.
  • AdvertiseCompare README logo placements, previews and monthly prices, or promote a plugin or extension.
PricingEnterpriseOpen AppInstall Guard
  1. Guard
  2. Security
  3. CVEs
  4. CVE 2021 33655 cve program container
HOL Guard

Public security guidance for teams protecting AI harnesses, MCP servers, skills, prompts, and local tool execution.

Install Guard

AI Security

  • Prompt injection
  • MCP security
  • OWASP MCP mapping
  • Supply chain

Resources

  • Trust packet
  • Harness setup
  • Redacted warnings
  • Safe labs

Product

  • Install Guard
  • Pricing
  • Open dashboard
Guard
  • Guard Overview
  • Releases
  • Contributors
  • Install Guard
  • Pricing
Docs
  • Documentation Index
  • Developer Hub
  • API Reference
  • Root OpenAPI
  • Registry OpenAPI
  • Run in Postman
  • Standards
  • Submit ERC-8004 Contract
  • Feature Your Agent
Best Plugins
  • Browse Plugins
  • Plugin Launches
  • Best Claude Plugins
  • Best Codex Plugins
  • Best Grok Plugins
  • Best Kimi Plugins
  • Best DeepSeek Plugins
  • Best Antigravity Plugins
  • Best MCP Servers
  • Best Cursor Plugins
  • Best OpenCode Plugins
Best Agents
  • Best ERC-8004 Agents
  • Best Virtuals Agents
  • Best MCP Servers
  • Best A2A Agents
  • Best x402 Payable
  • All Categories
Community
  • Telegram
  • X
More
  • About HOL
  • Sponsor
  • Advertise
  • Contact
  • Blog
  • GitHub
  • Privacy
  • Terms of Service
Settings

Copyright © 2026 HOL DAO LLC. All rights reserved.

Back to active CVEs
Unknown severity · Source severity not reportedCVE-2021-33655

CVE Program ContainerCVE-2021-33655

Answer in brief

CVE-2021-33655 records a Unknown severity vulnerability in CVE Program Container. The current sources do not mark it as known exploited. The current feed maps n/a/kernel (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 18, 2022Updated Oct 14, 2026Source checked Oct 14, 2026First seen by HOL Oct 14, 2026Material review Oct 14, 2026
Upstream Advisory

Key facts

Risk
Unknown severitySource severity not reported
Exploitation
Not marked as known exploited
Affected software
2 mapped packages or products
Fix availability
Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps n/a/kernel (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
PackageAffected rangeFixed version
n/a/kernelgeneric5.18 5.19.0-rc1Not reported
Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric>=0 <V1.1V1.1

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for n/a/kernel, Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem.
  2. 2Review the reported fix. Update Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem to V1.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

  1. Published upstream

    Jul 18, 2022

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Oct 14, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Oct 14, 2026

Sources and claim methodology

  • Source referencecert-portal.siemens.com
  • Source referencegit.kernel.org
  • Source referencelists.debian.org
  • Source referencedebian.org
  • Source referenceopenwall.com
Upstream source description

When sending malicous data to kernel by ioctl cmd FBIOPUT_VSCREENINFO,kernel will write memory out of bounds.

Quoted source text, attributed separately from HOL analysis.

Related CVEs

  • Gstreamer1-plugins-bad-free: gstreamer1-plugins-bad-free: out-of-bounds write in gst_h266_parser_parse_dci() due to off-by-one array bound checkAlso CWE-787
  • Gstreamer1-plugins-bad-free: gstreamer1-plugins-bad-free: heap out-of-bounds write in asfmux due to incorrect utf-16 size calculation for non-bmp charactersAlso CWE-787
  • Gstreamer1-plugins-base: gst-plugins-base: heap buffer overflow via unvalidated gstvideometa plane extents in gst_video_frame_map_id and video_meta_deserializeAlso CWE-787
  • WPCode 2.0.0 - 2.3.9 - Unauthenticated Snippet Suppression via Safe Mode BypassSame generic ecosystem
  • Stack overwrite from specially formatted base64 RDATA fieldSame generic ecosystem
  • Stack overwrite from a specially crafted and formatted SVCB or HTTPS RRSame generic ecosystem

Record context

Vulnerability class
Memory Corruption
EPSS
Not reported
CWE IDs
CWE-787
Source
CVE List V5
Source checked
Oct 14, 2026
References
5 linked sources
Open source record