CVE-2023-50262 Dompdf possible DoS caused by infinite recursion when parsing SVG images
An attacker can cause a denial of service in Dompdf by sending malicious SVG images that trigger infinite recursion, exhausting system resources.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-50262?
CVE-2023-50262 is a medium-severity denial of service vulnerability in dompdf, published on 13 Dec 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Dompdf is an HTML to PDF converter for PHP. When parsing SVG images Dompdf performs an initial validation to ensure that paths within the SVG are allowed. One of the validations is that the SVG document does not reference itself. However, prior to version 2.0.4, a recursive chained using two or more SVG documents is not correctly validated. Depending on the system configuration and attack pattern this could exhaust the memory available to the executing process and/or to the server itself.
php-svg-lib, when run in isolation, does not support SVG references for `image` elements. However, when used in combination with Dompdf, php-svg-lib will process SVG images referenced by an `image` element. Dompdf currently includes validation to prevent self-referential `image` references, but a chained reference is not checked. A malicious actor may thus trigger infinite recursion by chaining references between two or more SVG images.
When Dompdf parses a malicious payload, it will crash due after exceeding the allowed execution time or memory usage. An attacker sending multiple request to a system can potentially cause resource exhaustion to the point that the system is unable to handle incoming request.
Version 2.0.4 contains a fix for this issue.
Which versions are affected by CVE-2023-50262?
2 open source packages ship an affected version, including dompdf/dompdf. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
dompdf/dompdf Packagist | All versions | 2.0.4 |
dompdf/dompdf Packagist | All versions | 2.0.4 |
Products include Dompdf Project Dompdf.
How do I fix CVE-2023-50262?
Upgrade dompdf/dompdf to 2.0.4 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-50262 being exploited?
There is no known exploitation of CVE-2023-50262 in the wild and no public exploit code.
Other vulnerabilities in dompdf
- CVE-2023-24813 URI validation failure on SVG parsing. Bypass of CVE-2023-23924
- CVE-2023-23924 URI validation failure on SVG parsing in Dompdf
- CVE-2021-3838 PHAR Deserialization in dompdf/dompdf
- CVE-2021-3902 Improper Restriction of XML External Entity Reference in dompdf/dompdf
- CVE-2022-28368 Remote code injection in dompdf/dompdf
Sources
Also known as DEBIAN-CVE-2023-50262, GHSA-3qx2-6f78-w2j2.