CVE-2021-25641: apache software foundation apache dubbo Deserialization of Untrusted Data
Vulnerability summary
CVE-2021-25641 is a critical (CVSS 9.8) Deserialization of Untrusted Data vulnerability in apache software foundation apache dubbo. EPSS estimates a 21.22% chance of exploitation in the next 30 days, higher than 97.5% of scored vulnerabilities.
Timeline
- 29-05-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
3 scores · 2 sources · 2 versions- OSV · MavenEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
21.22%
Chance of exploitation in the next 30 days
Percentile
98%
Versus all other CVEs
30-day change
0.00 pp
From 21.22% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Apache1 product
- dubbo≥ 2.5.0, < 2.6.9 | ≥ 2.7.0, < 2.7.8
Apache software foundation1 product
- apache dubbo≥ Apache Dubbo 2.7.x, < 2.7.8 | ≥ Apache Dubbo 2.6.x, < 2.6.9
Com.alibaba1 product
- dubbo≥ 2.5.0, < 2.6.9
Org.apache.dubbo1 product
- dubbo≥ 2.5.0, < 2.7.8
4 vendors · 4 products
