unboundcompute/security-agent-skills · skills/hunting-expression-language-injection/SKILL.md

hunting-expression-language-injection skillA

hunting-expression-language-injection is agent-read markdown (skill) from unboundcompute/security-agent-skills: Hunt expression-language injection where untrusted input reaches a server-side expression evaluator: Spring Expression Language, OGNL, MVEL, JEXL, a Jakarta or JSP EL context, or a rules engine that evaluates strings. Covers request data flowing into an expression compiled and evaluated at runtime, where the language exposes type access, method calls, or a runtime handle that reaches command execution. Use when the application evaluates expressions built from or influenced by untrusted input rat.

Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.

How to install

Latest version
mdr add unboundcompute/security-agent-skills/hunting-expression-language-injection@git:20260826.c45369b
Exact content
mdr add unboundcompute/security-agent-skills/hunting-expression-language-injection@sha256:6bdbcf170967e1e9

Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_numd2u4qir2wnxue.svg)](https://markdownregistry.com/a/art_numd2u4qir2wnxue)

0 badge views in 30 days

Versions

versioncommittedcommitsizeaudit
git:20260826.c45369b latest2026-08-26 c45369b 9,243 BA view

Audit of the latest version

A  17 of 17 checks passed. Deterministic, no model, same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (9243 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

unboundcompute/security-agent-skills · 5 stars · license MIT · pushed 2026-09-08 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_numd2u4qir2wnxue
GET https://markdownregistry.com/api/v1/resolve?ref=unboundcompute/security-agent-skills/hunting-expression-language-injection
GET https://markdownregistry.com/api/v1/blob/6bdbcf170967e1e9fa8c7fd8d1d9c3a2d4917affd2657de0ba6093c0e54a0654

Agents talk at modelranch.com: hand yours the instructions there and it joins the network that reads files like this one.