CtrlK
BlogDocsLog inGet started
Tessl Logo
SkillPublic

broken-authentication

Identify and exploit authentication and session management vulnerabilities in web applications. Broken authentication consistently ranks in the OWASP Top 10 and can lead to account takeover, identity theft, and unauthorized access to sensitive systems.

Quality

66%

Does it follow best practices?

Run evals on this skill

Adds up to 20 points to the overall score

View guide
SecuritybySnyk

Passed

No findings from the security scan

Fix and improve this skill with Tessl

tessl review fix ./skills/broken-authentication/SKILL.md
SKILL.md
Quality
Evals
Security

Quality

Content

63%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

This is a well-structured, largely actionable testing methodology with clear sequencing and appropriate authorization gating for a sensitive offensive-security topic. Its weaknesses are length and monolithic structure: known-to-Claude reference material, payload lists, and worked examples are inlined rather than split into reference files, and a few code examples are incomplete stubs. Trimming the redundant material and externalizing the quick-reference content would meaningfully improve token efficiency.

Suggestions

Move the Quick Reference (vulnerability table, credential payload lists, cookie-flag table, bypass headers) and the three worked Examples into a references/ file (e.g., references/payloads.md, references/examples.md) linked from a short overview section, cutting SKILL.md substantially.

Delete or replace the 'When to Use' filler sentence ('This skill is applicable to execute the workflow or actions described in the overview') with concrete applicability conditions, and remove default credential/cookie-flag explanations Claude already knows.

Complete the session-token analysis script (entropy/sequential-pattern checks) or convert it to an explicit checklist of concrete checks, and fix the broken code fence in Phase 3 around the password-reset/API-response snippets.

DimensionReasoningScore

Conciseness

The body is mostly structured commands and test checklists rather than concept prose, but it includes content Claude already knows — default credential lists (admin:admin, 123456), a cookie-flag table explaining HttpOnly/Secure/SameSite, 'credential stuffing differs from brute force' — plus a duplicated Quick Reference and a filler 'When to Use' sentence ('applicable to execute the workflow or actions described in the overview'). It could be tightened considerably without losing value.

3 / 5

Actionability

Mostly executable guidance: a ready-to-run Hydra command, concrete Burp Intruder payload-position steps, raw HTTP request examples, rate-limit bypass headers, and a worked JWT 'none' algorithm attack. Minor gaps keep it below 5: the session-token Python script stops at token collection with analysis left as comments, several phases (e.g., password policy testing) are comment-only checklists, and Phase 3 has a broken code fence around the password-reset/API-response snippets.

4 / 5

Workflow Clarity

Ten phases are clearly sequenced from mechanism analysis through password reset testing, with prerequisites, deliverables, an authorization confirmation gate with explicit numbered checkpoints, pre-agreed stop conditions, and a troubleshooting table that acts as error-recovery feedback. Not a 5 because mid-workflow validation checkpoints (e.g., verify lockout threshold before proceeding, re-confirm scope between phases) are mostly implicit.

4 / 5

Progressive Disclosure

The body is a ~497-line monolith with no bundle files; quick-reference tables, credential payload lists, and worked examples (JWT attack, reset-token exploitation) that clearly belong in separate reference files are all inline. Section headers are well organized, which lifts it above a 2, but content that should be split out is inlined with no one-level-deep reference structure.

3 / 5

Total

14

/

20

Passed

Description

53%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

The description states a clear domain and a what-action but stops short of being a strong trigger. It reads as a topical summary with impact justification rather than a capability-plus-trigger statement. Adding an explicit 'Use when...' clause with natural trigger terms would substantially improve it.

Suggestions

Append an explicit trigger clause, e.g., 'Use when testing login forms, password reset flows, session cookies, or MFA during an authorized web application security assessment.'

Replace the OWASP ranking/impact sentence with 2-3 concrete capabilities (e.g., 'test password policies and lockouts, analyze session token entropy, attempt MFA and password-reset bypasses') to raise specificity.

Add natural synonyms users would actually say — 'login', 'brute force', 'credential stuffing', 'session hijacking' — to improve trigger term coverage.

DimensionReasoningScore

Specificity

The description names the domain ('authentication and session management vulnerabilities in web applications') and two actions ('Identify and exploit'), but does not list several specific capabilities (e.g., password policy testing, brute-force/lockout testing, MFA bypass, token analysis), and the second sentence is impact context rather than capability description.

3 / 5

Completeness

It clearly answers 'what' (identify and exploit authentication/session vulnerabilities in web applications) but contains no 'Use when...' clause or equivalent trigger guidance; per the rubric guideline a missing 'when' caps completeness at 3.

3 / 5

Trigger Term Quality

Terms like 'authentication', 'session management', 'account takeover', and 'OWASP Top 10' are relevant, but common natural phrases a user would say ('login', 'brute force', 'password', 'MFA', 'penetration test') are missing, and the second sentence ('consistently ranks in the OWASP Top 10 and can lead to...') is buzzword-heavy impact fluff rather than trigger content.

3 / 5

Distinctiveness Conflict Risk

'Authentication and session management vulnerabilities' defines a clear niche with distinct trigger terms (account takeover, session management), with only minor overlap risk against broader web-application-security or session-management-specific skills; it is not distinct enough for a 5 because it lacks explicit trigger phrases that fully separate it from adjacent security-testing skills.

4 / 5

Total

13

/

20

Passed

Validation

93%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

frontmatter_unknown_keys

Unknown frontmatter key(s) found; consider removing or moving to metadata

Warning

Total

15

/

16

Passed

Repository

sickn33/agentic-awesome-skills

Path

skills/broken-authentication/SKILL.md

Reviewed

Table of Contents

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.