CVE-2021-21702 php: NULL pointer dereference in SoapClient

Publication Date2021-01-26
SeverityCritical
TypeDenial of Service
Affected PHP Versions
  • 7.3.0 - 7.3.26
  • 7.4.0 - 7.4.14
  • 8.0.0 - 8.0.1

CVE Details

In PHP versions 7.3.x below 7.3.27, 7.4.x below 7.4.15 and 8.0.x below 8.0.2, when using the SOAP extension's SoapClient class to connect to a SOAP server, a malicious SOAP server could return malformed XML data as a response that would cause PHP to access a null pointer and thus cause a crash. This could lead to a Denial of Service.

Recommendations

If you are using the SoapClient in production, upgrade to 7.3.27 or later, 7.4.15 or later, or 8.0.2 or later. If you cannot upgrade, consider using a library such as phpro/soap-client, which does not use the SOAP extension.