HOMEVULNERABILITIESCVE-2020-25817
MEDIUM

CVE-2020-25817

CWE-611Published: June 8, 2021· Updated: Jun 17, 2026

4.8
CVSS v3.1

Official Description

SilverStripe through 4.6.0-rc1 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. When this developer utility is misused for purposes involving external or user submitted data in custom project code, it can lead to vulnerabilities such as XSS on HTML output rendered through this custom code. This is now mitigated by disabling external entities during parsing. (The correct CVE ID year is 2020 [CVE-2020-25817, not CVE-2021-25817]).

NVD Source

Technical Analysis

CVE-2020-25817 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.High
User InteractionRequired
ScopeChanged
Impact
ConfidentialityLow
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Affected Vendors & Products

silverstripe1 product(s)
silverstripe
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://forum.silverstripe.org/c/releases
ADVISORYhttps://www.silverstripe.org/blog/tag/release
ADVISORYhttps://www.silverstripe.org/download/security-releases/
ADVISORYhttps://forum.silverstripe.org/c/releases
ADVISORYhttps://www.silverstripe.org/blog/tag/release
ADVISORYhttps://www.silverstripe.org/download/security-releases/

All References (8)

→
https://forum.silverstripe.org/c/releasesRelease Notes · Vendor Advisory
→
https://www.silverstripe.org/blog/tag/releaseRelease Notes · Vendor Advisory
→
https://www.silverstripe.org/download/security-releases/Vendor Advisory
→
https://www.silverstripe.org/download/security-releases/cve-2020-25817Broken Link
→
https://forum.silverstripe.org/c/releasesRelease Notes · Vendor Advisory
→
https://www.silverstripe.org/blog/tag/releaseRelease Notes · Vendor Advisory
→
https://www.silverstripe.org/download/security-releases/Vendor Advisory
→
https://www.silverstripe.org/download/security-releases/cve-2020-25817Broken Link

Quick Facts

CVE IDCVE-2020-25817
CVSS Score4.8 / 10
SeverityMEDIUM
WeaknessCWE-611
CISA KEVNo
Affected1 vendor(s)
PublishedJun 8, 2021

Related CVEs (CWE-611)

CVE-2018-1000651
10.0
CVE-2015-9280
10.0
CVE-2017-7664
10.0
CVE-2018-1000644
10.0
CVE-2018-1000652
10.0
CVE-2023-38490
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-25817 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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