CVE-2018-15503

The unpack implementation in Swoole version 4.0.4 lacks correct size checks in the deserialization process. An attacker can craft a serialized object to exploit this vulnerability and cause a SEGV.

Weakness

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected Software

Potential Mitigations

• Make fields transient to protect them from deserialization.
• An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/586.html

References

• https://github.com/swoole/swoole-src/commit/4cdbce5d9bf2fe596bb6acd7d6611f9e8c253a76
• https://github.com/swoole/swoole-src/issues/1882
• https://x-c3ll.github.io/posts/swoole-deserialization-cve-2018-15503/
• https://github.com/swoole/swoole-src/commit/4cdbce5d9bf2fe596bb6acd7d6611f9e8c253a76
• https://github.com/swoole/swoole-src/issues/1882
• https://x-c3ll.github.io/posts/swoole-deserialization-cve-2018-15503/