Remote Code Execution Vulnerability in Session Storage
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-502.
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ratpack | ratpack | before 1.9.0 | 1.9.0 | Patch available | CNA |
| — | io.ratpack:ratpack-core (Maven) | before 1.9.0 | 1.9.0 | Patch available | GHSA-hc33-32vw-rpp9 |
- ratpack Vendorratpack Affected before 1.9.0 Fixed in 1.9.0 Patch available CNA
- io.ratpack:ratpack-core (Maven) Vendor— Affected before 1.9.0 Fixed in 1.9.0 Patch available GHSA-hc33-32vw-rpp9
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:ratpack_project:ratpack:*:*:*:*:*:*:*:* | before 1.9.0 | Vulnerable | Ratpack Project |
- cpe:2.3:a:ratpack_project:ratpack:*:*:*:*:*:*:*:* Versions before 1.9.0 Vulnerable ·Ratpack Project
Remediation
- Fix · CNA ratpack (ratpack) Fixed in 1.9.0
- Fix · GHSA-hc33-32vw-rpp9 io.ratpack:ratpack-core (Maven) Fixed in 1.9.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2021-29485
- 2026-10-03 Alias added: GHSA-hc33-32vw-rpp9
References
More ratpack vulnerabilities
- TI-2021-10194 Client side sessions should not allow unencrypted storage CVSS 3.1HIGH 7.5
- TI-2021-10192 Cached redirect poisoning via X-Forwarded-Host header CVSS 3.1HIGH 7.0
- TI-2019-08035 Cross-site scripting in io.ratpack:ratpack-core CVSS 3.1MEDIUM 6.1
- TI-2021-10193 Default client side session signing key is highly predictable CVSS 3.1MEDIUM 4.4
Sources
- CVE-2021-29485 · CVE Program
- CVE-2021-29485 · NVD
- FIRST EPSS
- GHSA-hc33-32vw-rpp9 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences