CVE-2020-35488

The fileop module of the NXLog service in NXLog Community Edition 2.10.2150 allows remote attackers to cause a denial of service (daemon crash) via a crafted Syslog payload to the Syslog service. This attack requires a specific configuration. Also, the name of the directory created must use a Syslog field. (For example, on Linux it is not possible to create a .. directory. On Windows, it is not possible to create a CON directory.)

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/GuillaumePetit84/CVE-2020-35488
• https://gitlab.com/nxlog-public/nxlog-ce/-/blob/master/ChangeLog.txt#L2
• https://github.com/GuillaumePetit84/CVE-2020-35488
• https://gitlab.com/nxlog-public/nxlog-ce/-/blob/master/ChangeLog.txt#L2