What happened
An issue was discovered in Pivotal Spring Web Flow through 2.4.5. Applications that do not change the value of the MvcViewFactoryCreator useSpringBinding property which is disabled by default (i.e., set to 'false') can be vulnerable to malicious EL expressions in view states that process form submissions but do not have a sub-element to declare explicit data binding property mappings. NOTE: this issue exists because of an incomplete fix for CVE-2017-4971.
Affected versions
Spring Web Flow Spring Web Flow 2.4.0 to 2.4.5 and Older unsupported versions are also affected: Spring Web Flow Spring Web Flow 2.4.0 to 2.4.5 and Older unsupported versions are also affected Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.