Applications that use UriComponentsBuilder to parse an externally provided URL (e.g. through a query parameter) AND perform validation checks on the host of the parsed URL may be vulnerable to a open redirect attack or to a SSRF attack if the URL is used after passing validation checks.

Spring Framework

• 6.1.0 - 6.1.3
• 6.0.0 - 6.0.16
• 5.3.0 - 5.3.31
• Older, unsupported versions are also affected

Upgrade Spring Framework as follows:

• 6.1.x users should upgrade to 6.1.4
• 6.0.x users should upgrade to 6.0.17
• 5.3.x users should upgrade to 5.3.32

No other steps are necessary.

The issue was identified and responsibly reported by Sean Pesce from Motorola Solutions.