CVE-2021-25641

Critical

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.

SeverityCritical
CVSS9.8
Exploit probability—
ProductApache Dubbo
PublishedJun 1, 2021
First seenJun 1, 2021

How to fix

Update
  • apache dubbo2.6.9, 2.7.8 or later
  • org.apache.dubbo:dubbo2.7.8 or later
  • com.alibaba:dubbo2.6.9 or later

Affected products

ProductAffected versionsFixed in
apache dubbo2.5.0 ≤ v < 2.6.9, 2.7.0 ≤ v < 2.7.82.6.9, 2.7.8
org.apache.dubbo:dubboMaven2.5.0 ≤ v < 2.7.82.7.8
com.alibaba:dubboMaven2.5.0 ≤ v < 2.6.92.6.9

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CVE-2021-25641 · Apache Dubbo · Dark Radar