KnpLabs/snappy

PhpWeasyPrint is a PHP library allowing PDF generation from a URL or an HTML page. Prior to version 2.6.0, `pontedilana/php-weasyprint` guarded the output filename against the `phar://` stream wrapper with a case-sensitive blacklist. PHP stream wrappers are case-insensitive, so `PHAR://`, `Phar://`, etc. bypass the check and reach `fileExists()` (`file_exists()`) in `prepareOutput()`. On PHP 7 (which the library still supports — PHP 7.4+), this triggers deserialization of a crafted PHAR archive's metadata, leading to remote code execution. This is the patch-bypass of CVE-2023-28115. The same issue and fix were handled upstream in KnpLabs/snappy (GHSA-92rv-4j2h-8mjj). PhpWeasyPrint version 2.6.0 contains a patch for the issue.

PhpWeasyPrint is a PHP library allowing PDF generation from a URL or an HTML page. Prior to version 2.6.0, `pontedilana/php-weasyprint` fetches the content of option values server-side via `file_get_contents()` when the value looks like a URL, without restricting the URL scheme. The `attachment` option of `Pdf` is the reachable sink: any value that passes `isOptionUrl()` (`filter_var(..., FILTER_VALIDATE_URL)`) is downloaded by the PHP process and embedded into the generated PDF. Because `FILTER_VALIDATE_URL` accepts `http`, `https`, `ftp`, `file` and PHP stream wrappers such as `php://`, an attacker who can influence the `attachment` value reaches both a **Server-Side Request Forgery** primitive (e.g. internal HTTP endpoints, cloud metadata) and a local file disclosure primitive (`file://`, `php://filter/...`), with the fetched bytes exfiltrated as a PDF attachment. This is the same class of issue KnpLabs/snappy patched for its `xsl-style-sheet` option in GHSA-c5fp-p67m-gq56. The library is documented as a one-to-one substitute for KnpLabs/snappy and shares the same code shape. PhpWeasyPrint version 2.6.0 contains a patch for the issue.

PhpWeasyPrint is a PHP library allowing PDF generation from a URL or an HTML page. Prior to version 2.5.1, `pontedilana/php-weasyprint` builds the shell command for WeasyPrint by passing the binary path through `escapeshellarg()` first and then checking the *quoted* result with `is_executable()`. On POSIX `escapeshellarg('/usr/local/bin/weasyprint')` returns `'/usr/local/bin/weasyprint'` with the single-quote characters as part of the string, so `is_executable()` looks for a file whose actual name includes those quotes. That file never exists, the "safe" branch is dead code, and the raw `$binary` string (set via the constructor or `setBinary()`) flows directly into `Symfony\Component\Process\Process::fromShellCommandline()`. Any deployment whose binary path is sourced from configuration, an environment variable, or a per-tenant setting reaches a shell-command-injection sink. The library is documented as a one-to-one substitute for KnpLabs/snappy and inherited the exact pre-fix codepath KnpLabs patched in GHSA-vpr4-p6fq-85jc. PhpWeasyPrint version 2.5.1 contains a patch for the issue.

PhpWeasyPrint is a PHP library allowing PDF generation from a URL or an HTML page. Prior to version 2.6.0, `AbstractGenerator::$temporaryFiles` is a public array, and `removeTemporaryFiles()` — invoked from `__destruct()` and from a registered shutdown function — calls `unlink()` on every entry without verifying that the path is contained within the temporary folder. Any code holding a reference to a generator instance can push an arbitrary path into the array and have it deleted on script shutdown. This mirrors the KnpLabs/snappy issue GHSA-87qc-37cw-84h4. PhpWeasyPrint version 2.6.0 contains a patch for the issue.

Snappy is a PHP library allowing thumbnail, snapshot or PDF generation from a url or a html page. Prior to version 1.7.0, there is a SSRF and local file read vulnerability via the xsl-style-sheet option. This issue has been patched in version 1.7.0.

Snappy is a PHP library allowing thumbnail, snapshot or PDF generation from a url or a html page. Prior to version 1.7.1, on POSIX, escapeshellarg(‘/usr/bin/wkhtmltopdf’) returns the literal string ‘/usr/bin/wkhtmltopdf’ with the single-quote characters included. is_executable() then looks for a file whose actual name contains those quote characters, which essentially never exists. The safe branch is dead code and $command always falls through to the raw, unescaped value. The rest of the arguments (options, input, output) are escaped correctly, so injection has to land in the binary string itself. That happens whenever the binary path is sourced from configuration that is user-influenced, derived from environment variables that ultimately come from request data, or concatenated with any user-controlled fragment. This issue has been patched in version 1.7.1.

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.

Snappy is a PHP library allowing thumbnail, snapshot or PDF generation from a url or a html page. Prior to version 1.4.2, Snappy is vulnerable to PHAR deserialization due to a lack of checking on the protocol before passing it into the `file_exists()` function. If an attacker can upload files of any type to the server he can pass in the phar:// protocol to unserialize the uploaded file and instantiate arbitrary PHP objects. This can lead to remote code execution especially when snappy is used with frameworks with documented POP chains like Laravel/Symfony vulnerable developer code. If a user can control the output file from the `generateFromHtml()` function, it will invoke deserialization. This vulnerability is capable of remote code execution if Snappy is used with frameworks or developer code with vulnerable POP chains. It has been fixed in version 1.4.2.