CVE-2021-25641
Severity CVSS v4.0:
Pending analysis
Type:
CWE-502
Deserialization of Untrusted Dat
Publication date:
01/06/2021
Last modified:
10/06/2021
Description
Each Apache Dubbo server will set a serialization id to tell the clients which serialization protocol it is working on. But for Dubbo versions before 2.7.8 or 2.6.9, an attacker can choose which serialization id the Provider will use by tampering with the byte preamble flags, aka, not following the server's instruction. This means that if a weak deserializer such as the Kryo and FST are somehow in code scope (e.g. if Kryo is somehow a part of a dependency), a remote unauthenticated attacker can tell the Provider to use the weak deserializer, and then proceed to exploit it.
Impact
Base Score 3.x
9.80
Severity 3.x
CRITICAL
Base Score 2.0
7.50
Severity 2.0
HIGH
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:a:apache:dubbo:*:*:*:*:*:*:*:* | 2.5.0 (including) | 2.6.9 (excluding) |
| cpe:2.3:a:apache:dubbo:*:*:*:*:*:*:*:* | 2.7.0 (including) | 2.7.8 (excluding) |
To consult the complete list of CPE names with products and versions, see this page



