HIGH

CVE-2020-26258

CVSS v3

7.7

HIGH

EPSS Score

93.7%

exploit probability

CISA KEV

No

known exploited

Exploitation

SSVC status

Description

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.15, a Server-Side Forgery Request vulnerability can be activated when unmarshalling. The vulnerability may allow a remote attacker to request data from internal resources that are not publicly available only by manipulating the processed input stream. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.15. The reported vulnerability does not exist if running Java 15 or higher. No user is affected who followed the recommendation to setup XStream's Security Framework with a whitelist! Anyone relying on XStream's default blacklist can immediately switch to a whilelist for the allowed types to avoid the vulnerability. Users of XStream 1.4.14 or below who still want to use XStream default blacklist can use a workaround described in more detailed in the referenced advisories.

Technical details

Published
12/16/2020

Frequently asked questions

What is CVE-2020-26258?

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.15, a Server-Side Forgery Request vulnerability can be activated when unmarshalling. The vulnerability may allow a remote attacker to request data from internal resources that are not publicly available only by manipulating the processed input stream. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.15. The reported vulnerability does not exist if running Java 15 or higher. No user is affected who followed the recommendation to setup XStream's Security Framework with a whitelist! Anyone relying on XStream's default blacklist can immediately switch to a whilelist for the allowed types to avoid the vulnerability. Users of XStream 1.4.14 or below who still want to use XStream default blacklist can use a workaround described in more detailed in the referenced advisories.

Is CVE-2020-26258 actively exploited?

Active exploitation of CVE-2020-26258 has not been confirmed. The EPSS score is 93.7%, indicating the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-26258?

CVE-2020-26258 has a CVSS v3 base score of 7.7 (HIGH severity).

Is CVE-2020-26258 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.