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Insecure File Uploads · asdfgh1445 | DecimalAI

securityby asdfgh1445

Insecure File Uploads

asdfgh1445/Strix•不安全文件上传

Source asdfgh1445/ctf-super-hub ↗License NOASSERTION

Strix 文件上传安全测试手册,覆盖扩展名绕过、Content-Type 操控与路径穿越;触发名:strix-insecure-file-uploads

SkillScore96Maintained

Automatic

Security & AppSec pack

Last verified 8/16/2026

What it changes

Passed 22 of 23 test cases with the skill, and 21 of 23 without it.

Without skill91%

With skill96%

Checks it passed that the model alone missed

Recommends setting directory permissions to octal mode 700 or 750 owned by the web service user.

1 fixed21 passed either way1 still failing0 broke

Pass-rate lift: +4 pp
Tokens: +87%
Agent turns: 0%
Response time: +1%

Model gemini-3.6-flashMeasured 8/16/2026v122 of 23 cases passed with skill

Tokens, turns and time describe resource use, not a dollar price.

Use this skill

Save it into your project's skills folder. Claude Code picks it up in its next session.

curl -fsSL --create-dirs -o .claude/skills/asdfgh1445-strix-55fc58/SKILL.md https://app.decimal.ai/s/asdfgh1445-strix-20a361/SKILL.md

Want it pinned and updatable? pip install "decimalai>=0.15", then decimalai skills add asdfgh1445-strix-20a361, and start Claude Code with claude --plugin-dir "$(git rev-parse --show-toplevel)/.agents"

1 · One-time — install the CLI (docs ↗)

pip install "decimalai>=0.15"

2 · Get the skill — writes .agents/skills/asdfgh1445-strix-55fc58/ and pins it in .decimal/skills.lock

decimalai skills add asdfgh1445-strix-20a361

No CLI? Get the same file — curl · raw file

curl -fsSL --create-dirs -o .claude/skills/asdfgh1445-strix-55fc58/SKILL.md https://app.decimal.ai/s/asdfgh1445-strix-20a361/SKILL.md

Raw file: /s/asdfgh1445-strix-20a361/SKILL.md ↗ · machine-readable summary at /s/asdfgh1445-strix-20a361.json ↗

Safety checks: 3 of 3 passed

Code scan CleanIntent PassedContent Clean

See it in action

A test case the skill fixed. Same model, same prompt, with and without the skill.

Prompt

When storing user-uploaded files in a temporary Linux directory prior to virus scanning, what directory permission bits should be set to prevent other system users from reading or altering the pending files?

What was checked, without and with the skill
Checked	Without skill	With skill
Recommends setting directory permissions to octal mode 700 or 750 owned by the web service user.	Missed	Passed

case-21 · gemini-3.6-flash · 8/16/2026 · answers are capped and redacted

What's inside

The instructions your model reads when the skill loads.

SKILL.md183 linessingle file

Insecure File Uploads

Upload surfaces are high risk: server-side execution (RCE), stored XSS, malware distribution, storage takeover, and DoS. Modern stacks mix direct-to-cloud uploads, background processors, and CDNs—authorization and validation must hold across every step.

Attack Surface

Web/mobile/API uploads, direct-to-cloud (S3/GCS/Azure) presigned flows, resumable/multipart protocols (tus, S3 MPU)
Image/document/media pipelines (ImageMagick/GraphicsMagick, Ghostscript, ExifTool, PDF engines, office converters)
Admin/bulk importers, archive uploads (zip/tar), report/template uploads, rich text with attachments
Serving paths: app directly, object storage, CDN, email attachments, previews/thumbnails

Reconnaissance

Surface Map

Endpoints/fields: upload, file, avatar, image, attachment, import, media, document, template
Direct-to-cloud params: key, bucket, acl, Content-Type, Content-Disposition, x-amz-meta-*, cache-control
Resumable APIs: create/init → upload/chunk → complete/finalize; check if metadata/headers can be altered late
Background processors: thumbnails, PDF→image, virus scan queues; identify timing and status transitions

Capability Probes

Small probe files of each claimed type; diff resulting Content-Type, Content-Disposition, and X-Content-Type-Options on download
Magic bytes vs extension: JPEG/GIF/PNG headers; mismatches reveal reliance on extension or MIME sniffing
SVG/HTML probe: do they render inline (text/html or image/svg+xml) or download (attachment)?
Archive probe: simple zip with nested path traversal entries and symlinks to detect extraction rules

Detection Channels

Server Execution

Web shell execution (language dependent), config/handler uploads (.htaccess, .user.ini, web.config) enabling execution
Interpreter-side template/script evaluation during conversion (ImageMagick/Ghostscript/ExifTool)

Client Execution

Stored XSS via SVG/HTML/JS if served inline without correct headers; PDF JavaScript; office macros in previewers

Header and Render

Track record

Benchmark

22 / 23

test cases passed, vs 21 / 23 without

Adoption

Users: 0
Times used: 0

Safety and source details

SkillSafety

✓ 3 of 3 passed

Code scan15 of 15 checks clean

0 critical · 0 warning · 0 info — scanner v4 — 8/3/2026

View 15 scanner checks

live_secretremote_code_executionreverse_shelldata_exfiltrationssrf_metadataagent_snoopinganti_refusaldestructive_commandsobfuscated_unicodeunicode_homoglyphopaque_blobsuspicious_urltool_overreachtrigger_abuseprompt_injection_phrasing

IntentSafe

LLM judge · does the skill do what it claims

ContentClean

LLM judge · policy & harmful-content review

Source

Imported

asdfgh1445 / ctf-super-hub

strix-insecure-file-uploads/SKILL.md

View on GitHub ↗

License NOASSERTIONImported 8/3/2026Version v1

More skills from the same source and nearby in the registry, with their headline benchmark lift.

Ready to supercharge your AI agents?

See it in action

What's inside

Insecure File Uploads

Attack Surface

Reconnaissance

Surface Map

Capability Probes

Detection Channels

Server Execution

Client Execution

Header and Render

Track record

Benchmark

Adoption

SkillSafety

Source

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