CVE-2021-29485 json
Remote Code Execution Vulnerability in Session Storage
published 2021-06-29 5 y ago modified 2026-07-08 4 mo ago also GHSA-hc33-32vw-rpp9 , EUVD-2021-1475
- cvss
- 9.9
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.0%
- EPSS 2.0% chance of exploitation in 30 days, percentile 80%
- public exploits
- 0
- none known
Summary
Ratpack is a toolkit for creating web applications. In versions prior to 1.9.0, a malicious attacker can achieve Remote Code Execution (RCE) via a maliciously crafted Java deserialization gadget chain leveraged against the Ratpack session store. If one's application does not use Ratpack's session mechanism, it is not vulnerable. Ratpack 1.9.0 introduces a strict allow-list mechanism that mitigates this vulnerability when used. Two possible workarounds exist. The simplest mitigation for users of earlier versions is to reduce the likelihood of attackers being able to write to the session data store. Alternatively or additionally, the allow-list mechanism could be manually back ported by providing an alternative implementation of `SessionSerializer` that uses an allow-list.
Patch / fix
- maven io.ratpack:ratpack-core 1.9.0
- ratpack_project ratpack 1.9.0
Exploit prediction
1.99% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| NVD | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 6.5 | AV:N/AC:L/Au:S/C:P/I:P/A:P |
| GitHub | 3.1 | 9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| maven | io.ratpack:ratpack-core | <1.9.0 |
1.9.0 |
Affected products
- ratpack ratpack
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
References
-
github.com
/ratpack/ratpack/security/advisories/GHSA-hc33-32vw-rpp9
web, third-party-advisory
-
mvnrepository.com
/artifact/io.ratpack/ratpack-core
web, release-notes, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-29485
advisory
-
github.com
/ratpack/ratpack
package
Sources
- CVE List CVE-2021-29485
- GitHub Advisory GHSA-hc33-32vw-rpp9
- NVD CVE-2021-29485
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