config-file-parsing-bugs SKILL.md skillA
config-file-parsing-bugs from dreadnode/capabilities is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add dreadnode/capabilities/config-file-parsing-bugs@git:20260529.17de87fPins git:20260529.17de87f in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- dreadnode/capabilities
- Path
capabilities/web-security/skills/config-file-parsing-bugs/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260529.17de87f, committed May 29, 2026
- Size
- 4,026 bytes
- Repository stars
- 22
- License
- MIT
Exploit config file parser vulnerabilities: line length truncation, duplicate section overwrites, encoding differentials, and fgets()-based C parser bugs. Use when target processes INI/YAML/TOML/properties files, PAM configs, syslog, or any fgets()-based config parser.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Config File Parsing Bugs Config file parsers silently truncate, silently drop, and silently overwrite. When a security decision depends on parsed config, parser quirks become security bugs. ## Attack Surface Config file parsers are vulnerable when: 1. **Attacker can inject content** into a config file (admin panel, API, SSRF, file write) 2. **Parser has quirks** that differ from what the consumer expects 3. **Security decisions** depend on parsed values ## Techniques ### 1. Line Length Truncation C-based parsers using `fgets()` read a fixed number of bytes per line. Excess bytes remain in the input buffer and are read by the NEXT `fgets()` call as a new line. **inih (C INI parser):** Default `INI_MAX_LINE = 200` bytes. ```ini [section] key = AAAA...(195 bytes padding)...\nadmin = true ; Parser sees: ; Line 1 (200 bytes): "key = AAAA...(truncated)" ; Line 2 (remainder): "admin = true" <-- parsed as legitimate entry ``` **PAM pam_group:** `PAM_GROUP_BUFLEN = 1000` bytes, same pattern. **BSD syslog (RFC 3164):** 1024-byte message limit. Pad to 1024, inject newline + fake log entry. **Detection in source code:** ```c …
Read the whole file at its exact version.
How to install
mdr add dreadnode/capabilities/config-file-parsing-bugs@sha256:2da477a3ecd6206cThe line at the top of this page pins the label git:20260529.17de87f, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_6ulvx44ff5l562dz)
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Versions
The registry has recorded 1 version of this file, committed on May 29, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (4026 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
dreadnode/capabilities · 22 stars · license MIT · pushed 2026-11-02 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_6ulvx44ff5l562dz GET https://markdownregistry.com/api/v1/resolve?ref=dreadnode/capabilities/config-file-parsing-bugs GET https://markdownregistry.com/api/v1/blob/2da477a3ecd6206cb539aa09bbe87d077ba98007ce32f8b89be168d7da538072
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.