A user could provide an expression whose string length is longer than the ParserExpressionSizeLimit() configured on the CEL environment, and a memory allocation would occur proportional to the size of the input before the limit would be checked / enforced.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
Low
Partial disruption
CVSS Vector v4.0