How should we interpret CVSS severity scores?

CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, and whether compensating controls exist. A Medium CVSS on an exposed production system can be more urgent than a Critical on an isolated non-production host.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. Risk increases sharply when exploitation becomes reliable or widespread.

Q: Why do vulnerabilities keep reappearing in our environment?

Recurring findings usually come from incomplete asset discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host.

Q: How do we prioritize remediation without burning out the team?

Use a repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress so remediation is steady, not reactive.

Q: How can SynScan help reduce vulnerability risk over time?

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.

352,262

Total vulnerabilities in the database

skillctl: argument injection, path traversal in --dest, FIFO/device DoS, hardlink exfiltration, and commit-trailer forgery — skillctl

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Impact

Following the path-safety patches in GHSA-wx3m-whqv-xv47 (v0.1.2), a comprehensive multi-angle audit surfaced five further vulnerabilities, now patched in v0.1.3:

source_sha argument injection in git ls-tree (CRITICAL). InstalledSkill.source_sha deserialized from .skills.toml (committed, PR-mergeable) flowed unvalidated into git ls-tree -r -z <refspec> -- <path>. Because the refspec sits before --, an attacker who slipped a malicious .skills.toml into a PR could set source_sha = "--name-only" / --abbrev=0 / --output=… and corrupt the diff classifier (which drives pull / push destructive decisions), or forge a divergence state to trick push --on-divergence overwrite into clobbering the wrong content.
FIFO / device / socket denial-of-service in copy_dir_all (CRITICAL). The file-type branch only checked is_dir() / is_symlink(); a FIFO inside a skill folder fell through to fs::copy, which blocks indefinitely waiting for a writer. A character device like /dev/zero would read until OOM. Reachable on skillctl add against any adversarial library.
add --dest arbitrary-directory wipe in agent mode (HIGH). --dest accepted absolute paths and .. traversal without validation, so a single invocation skillctl add --dest /Users/victim/.ssh --on-conflict overwrite --skill <maliciously-named> would remove_dir_all arbitrary directories — no .skills.toml round-trip required. Reachable in any non-interactive / agent-driven workflow where flag values may be attacker-supplied.
Commit-message trailer forgery via skill names (HIGH). Skill names were spliced verbatim into git commit -m "update skill: <name>" and into the commit.message field of --json output. A skill named foo\nCo-Authored-By: evil@x produced a forged commit trailer that downstream tooling (Linear, GitHub commit-bot, release-notes scrapers) treats as real authorship metadata.
Hardlink exfiltration via the round-trip (HIGH). fs::symlink_metadata reports a regular file for hardlinks (shared inode), and fs::copy reads the target content. An untrusted agent writing <project>/my-skill/data as a hardlink to ~/.ssh/id_rsa would have shipped the SSH key content to the (possibly public) library on the next skillctl push or detect.

Patches

Fixed in v0.1.3:

InstalledSkill::validate rejects any source_sha that isn't 40–64 hex characters.
fs_util::copy_dir_all only allows regular files and directories; FIFO / socket / device / other special files are rejected with AppError::Config.
commands::add::resolve_destination rejects .. unconditionally and rejects absolute paths in non-interactive / --json mode.
New src/sanitize.rs module: validate_identifier (strict, no control bytes / newlines / ESC, used for skill name + individual tags) and validate_message_safe (lenient, allows \n + \t, rejects \r + DEL + C0/C1 controls, used for description and --message). Wired at the skill::discover and read_tags boundaries so poisoned skills are dropped silently and poisoned descriptions/tags are stripped from otherwise-valid skills.
fs_util::copy_dir_all checks metadata.nlink() > 1 on regular files (Unix) and refuses hardlinked content.

All checks are lexical or single-syscall (symlink_metadata, metadata). No canonicalize, no TOCTOU windows. 23 new unit + integration tests cover each rejection class; cargo test: 95 pass; clippy clean; cargo audit clean.

Workarounds

Upgrade to v0.1.3. Pre-patch mitigations are awkward but possible:

Audit every .skills.toml source_sha field before running skillctl pull / push / detect.
Audit library content for FIFO / device files and hardlinks before running skillctl add.
Never invoke skillctl add with attacker-controllable --dest values in agent / CI contexts.
Never use --message with attacker-controlled content.

Credit

The findings were surfaced by a maintainer-led multi-angle audit (6 parallel sub-agents, one per threat-model dimension) following the firebaguette audit that motivated v0.1.2. The methodology (cross-agent convergence to identify the most exploitable items) is documented in the project's internal decisions log; the strongest signal was the four-of-six independent convergence on the source_sha vector.

Resources

Fix commit: 28dfce3
Release: https://github.com/umanio-agency/skillctl/releases/tag/v0.1.3
Prior advisory (path-safety + symlinks): GHSA-wx3m-whqv-xv47

Published: Jun 22, 2026
Updated: Jun 23, 2026
GHSA: GHSA-74p7-6h78-gw8p
Severity: High
Exploit:
CISA KEV:

No technical information available.

CWEs:

OWASP TOP 10:

Affected Software
References

Software	From	Fixed in
skillctl	-	0.1.3

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.