CVE-2017-20164Network attack vector

Phishing redirects via unchecked BackURL

Published Jan 7, 2023 · Updated Apr 8, 2025

Open redirect in Symbiote SilverStripe Seed 6.0.0 through 6.0.2 allows remote attackers to send users to untrusted sites via crafted BackURL values. SecurityLoginExtension::onBeforeSecurityLogin reads BackURL from the request and redirects without verifying that the destination is a site-local URL. A victim must already be authenticated and follow the crafted link; the result is a credible phishing redirect, not direct code execution.

CVSS severity6.1
Medium
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Open redirect in Symbiote SilverStripe Seed 6.0.0 through 6.0.2 allows remote attackers to send users to untrusted sites via crafted BackURL values. SecurityLoginExtension::onBeforeSecurityLogin reads BackURL from the request and redirects without verifying that the destination is a site-local URL. A victim must already be authenticated and follow the crafted link; the result is a credible phishing redirect, not direct code execution.

The record

CVE
CVE-2017-20164
Published
Jan 7, 2023
Updated
Apr 8, 2025
Vendor
Symbiote
Product
SilverStripe Seed
Classifications
CWE-601, CAPEC-178
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 7, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.0.0
  2. Affected versionversion=6.0.1
  3. Affected versionversion=6.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Symbiote · SilverStripe Seedversion=6.0.0; version=6.0.1; version=6.0.2

Published CVSS scores

6.1GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-601URL Redirection to Untrusted Site ('Open Redirect')
CAPEC-178Cross-Site Flashing

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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