SSRF in Apache Struts
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.818 (99.6th percentile), scored .
High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.818 · newest: 0.818 · change: 0.000
Affected products
- Apache Struts
- X-Stream Xstream — versions < 1.4.15
- Xstream
- Debian Linux — versions 9.0, 10.0
- Fedoraproject Fedora — versions 33, 34, 35
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/x-stream/xstream/security/advisories/GHSA-4cch-wxpw-8p28 (Third Party Advisory, Mitigation)
- lists.apache.org/thread.html/r97993e3d78e1f5389b7b172ba9f308440830ce5f051ee6271… (Mailing List, Issue Tracking)
- lists.debian.org/debian-lts-announce/2020/12/msg00042.html (Mailing List, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (Mailing List)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (Mailing List)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (Mailing List)
- security.netapp.com/advisory/ntap-20210409-0005 (Third Party Advisory)
- www.debian.org/security/2021/dsa-4828 (Third Party Advisory)
- x-stream.github.io/CVE-2020-26258.html (Exploit, Third Party Advisory, Mitigation)
- af854a3a-2127-422b-91ae-364da2661108 (Issue Tracking, Mailing List)
Frequently asked questions
- What is CVE-2020-26258?
- CVE-2020-26258 is a medium-severity vulnerability in Apache Struts, classified under Server-Side Request Forgery (SSRF). CVSS score: 6.3/10. Published 2020-12-16.
- How severe is CVE-2020-26258?
- Medium severity. CVSS v3 base score is 6.3 out of 10.
- Is CVE-2020-26258 known to be exploited?
- 25 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.