CVE-2021-25641 in the critical feed json
Dubbo Zookeeper does not check serialization id
published 5y ago modified 4mo ago also GHSA-v2rg-8cwr-75g8 , EUVD-2022-1540
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 21.2%
- EPSS 21.2% chance of exploitation in 30 days, percentile 97%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- maven org.apache.dubbo:dubbo 2.7.8
- maven com.alibaba:dubbo 2.6.9
- Apache Software Foundation Apache Dubbo 2.6.9, 2.7.8
Is CVE-2021-25641 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
21.22% chance of exploitation in the next 30 days, higher than 97% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
| GitHub | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| maven | org.apache.dubbo:dubbo | >=2.5.0, <2.7.8 |
2.7.8 |
| maven | com.alibaba:dubbo | >=2.5.0, <2.6.9 |
2.6.9 |
Affected products
- Apache Software Foundation Apache Dubbo
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
References
-
lists.apache.org
/thread.html/r99ef7fa35585d3a68762de07e8d2b2bc48b8fa669a03e8d84b9673f3%40%3Cdev.dubbo.apache.org%3E
web, mailing-list, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-25641
advisory
Sources
- CVE List CVE-2021-25641
- GitHub Advisory GHSA-v2rg-8cwr-75g8
- NVD CVE-2021-25641
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