How severe is CVE-2023-41330?

CVE-2023-41330 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-41330?

CVE-2023-41330 affects the following packages: knplabs/knp-snappy (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2023-41330?

Update knplabs/knp-snappy to 1.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-41330 is resolved across your whole dependency graph.

How do I detect CVE-2023-41330 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for knplabs/knp-snappy. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2023-41330 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2023-41330?

O3 pinpoints whether CVE-2023-41330 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2023-41330 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2023-41330, including 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2023-41330?

CVE-2023-41330 has an EPSS (Exploit Prediction Scoring System) score of 1.9%, placing it in the 77th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2023-41330 published, and has it been updated?

CVE-2023-41330 was published on September 6, 2023 and was last updated on April 2, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

CVE-2023-41330

CRITICAL

Unsafe deserialization in knplabs/knp-snappy

Also known asGHSA-92rv-4j2h-8mjj

Published

Sep 6, 2023

Updated

Apr 2, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

2 known

EPSS Exploitation Probability

via FIRST.org ↗

1.9%probability of exploitation in next 30 days

Lower Risk77th percentile+0.29%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐘knplabs/knp-snappy

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

knplabs/knp-snappy is a PHP library allowing thumbnail, snapshot or PDF generation from a url or a html page.

Issue

On March 17th the vulnerability CVE-2023-28115 was disclosed, allowing an attacker to gain remote code execution through PHAR deserialization. Version 1.4.2 added a check if (\strpos($filename, 'phar://') === 0) in the prepareOutput function to resolve this CVE, however if the user is able to control the second parameter of the generateFromHtml() function of Snappy, it will then be passed as the $filename parameter in the prepareOutput() function. In the original vulnerability, a file name with a phar:// wrapper could be sent to the fileExists() function, equivalent to the file_exists() PHP function. This allowed users to trigger a deserialization on arbitrary PHAR files. To fix this issue, the string is now passed to the strpos() function and if it starts with phar://, an exception is raised. However, PHP wrappers being case insensitive, this patch can be bypassed using PHAR:// instead of phar://. A successful exploitation of this vulnerability allows executing arbitrary code and accessing the underlying filesystem. The attacker must be able to upload a file and the server must be running a PHP version prior to 8. This issue has been addressed in commit d3b742d61a which has been included in version 1.4.3. Users are advised to upgrade. Users unable to upgrade should ensure that only trusted users may submit data to the AbstractGenerator->generate(...) function.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`knplabs/knp-snappy`	all versions	1.4.3

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

knplabs/knp-snappy is a PHP library allowing thumbnail, snapshot or PDF …

github.comNVDSep 2023

knplabs/knp-snappy is a PHP library allowing thumbnail, snapshot or PDF …

github.comNVDSep 2023

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for knplabs/knp-snappy. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update knplabs/knp-snappy to 1.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-41330 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2023-41330 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2023-41330. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

knplabs/knp-snappy is a PHP library allowing thumbnail, snapshot or PDF generation from a url or a html page. ## Issue On March 17th the vulnerability CVE-2023-28115 was disclosed, allowing an attacker to gain remote code execution through PHAR deserialization. Version 1.4.2 added a check `if (\strpos($filename, 'phar://') === 0)` in the `prepareOutput` function to resolve this CVE, however if the user is able to control the second parameter of the `generateFromHtml()` function of Snappy, it will then be passed as the `$filename` parameter in the `prepareOutput()` function. In the original vu

O3 Security · Impact-Aware SCA

Is CVE-2023-41330 in your dependencies?

O3 detects CVE-2023-41330 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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