GHSA-92rv-4j2h-8mjj · Severity: critical · Ecosystem: composer — Snappy PHAR deserialization vulnerability
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.
Conclusion & alert: CVE-2023-41330 is rated High Exploit Risk (81.3/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.88%). Core evidence: 2 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ | |
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 1.58% | 1.88% | +0.29% |
| 2 | 2026-06-01 | 1.44% | 1.58% | +0.14% |
| 3 | 2026-04-28 | — | 1.44% | — |
Full EPSS history (26 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
GHSA-92rv-4j2h-8mjj · Severity: critical · Ecosystem: composer — Snappy PHAR deserialization vulnerability
| URL | Tags |
|---|---|
| https://github.com/KnpLabs/snappy/commit/d3b742d61a68bf93866032c2c0a7f1486128b67e | Patch |
| https://github.com/KnpLabs/snappy/security/advisories/GHSA-92rv-4j2h-8mjj | Exploit Mitigation Vendor Advisory |
| https://github.com/KnpLabs/snappy/security/advisories/GHSA-gq6w-q6wh-jggc | Exploit Vendor Advisory |