RCE in Apache Struts
CVE-2020-26259
XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.15, is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling. The vulnerability may allow a remote attacker to delete arbitrary know files on the host as log as the executing process has sufficient rights 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 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.
Vulnerability class: Command Injection (OS Command Injection)
EPSS: 0.824 (99.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N.
Affected products
- Apache Struts
- X-stream Xstream — versions < 1.4.15
- Xstream
- Debian Debian_linux — versions 9.0, 10.0
- Fedoraproject Fedora — versions 33, 34, 35
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory, Mitigation)
- security-advisories@github.com (Exploit, Third Party Advisory, x_refsource_MISC, Mitigation)
- security-advisories@github.com (mailing-list, x_refsource_MLIST, Mailing List, Issue Tracking)
- security-advisories@github.com (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- security-advisories@github.com (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (x_refsource_FEDORA, vendor-advisory, Mailing List)
- security-advisories@github.com (x_refsource_FEDORA, vendor-advisory, Mailing List)
- security-advisories@github.com (x_refsource_FEDORA, vendor-advisory, Mailing List)
Frequently asked questions
- What is CVE-2020-26259?
- CVE-2020-26259 is a medium-severity vulnerability in Apache Struts, classified under OS Command Injection. CVSS score: 6.8/10. Published 2020-12-16.
- How severe is CVE-2020-26259?
- Medium severity. CVSS v3 base score is 6.8 out of 10.
- Is CVE-2020-26259 known to be exploited?
- 25 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.