CVE-2021-39152: A Server-Side Forgery Request vulnerability in XStream via HashMap unmarshaling
A flaw was found in xstream, a simple library used to serialize objects to XML and back again. This flaw allows a remote attacker to request data from internal resources that are not publicly available by manipulating the processed input stream with Java runtime versions 14 to 8. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Other sources
XStream is a simple library to serialize objects to XML and back again. In affected versions this vulnerability may allow a remote attacker to request data from internal resources that are not publicly available only by manipulating the processed input stream with a Java runtime version 14 to 8. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.18.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
redhat/xstreamto a version that resolves this vulnerability.Fixed in 0:1.3.1-16.el7_9 - Upgrade
Upgrade
debian/libxstream-javato a version that resolves this vulnerability.Fixed in 1.4.11.1-1+deb10u3Fixed in 1.4.11.1-1+deb10u4Fixed in 1.4.15-3+deb11u2Fixed in 1.4.20-1 - Upgrade
Upgrade
redhat/xstreamto a version that resolves this vulnerability.Fixed in 1.4.18 - Upgrade
Upgrade
x-stream/xstreamto a version that resolves this vulnerability.Fixed in 1.4.18 - Configuration
Configure XStream's security framework using a whitelist limited to the minimal required types (instead of relying on the default blacklist only) to prevent the SSRF issue via HashMap unmarshaling.
XStream Security Framework (whitelist) default blacklist vs whitelist-limited configuration = whitelist limited to the minimal required types
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is CVE-2021-39152?
CVE-2021-39152 is a vulnerability in the XStream library that allows a remote attacker to request data from internal resources by manipulating the input stream.
How severe is CVE-2021-39152?
CVE-2021-39152 has a severity rating of 8.5, indicating a high severity level.
Which software is affected by CVE-2021-39152?
The XStream library versions 1.4.18 and below are affected by CVE-2021-39152.
How can I fix CVE-2021-39152?
To fix CVE-2021-39152, update the XStream library to version 1.4.19 or higher.
Where can I find more information about CVE-2021-39152?
You can find more information about CVE-2021-39152 at the following references: [link1], [link2], [link3].