CVE-2023-28370Public exploitNetwork attack vector

Phishing redirects via protocol-relative static paths

Published May 25, 2023 · Updated Nov 3, 2025

Open redirect in Tornado 6.3.1 and earlier allows remote attackers to send users to arbitrary sites through crafted URLs. StaticFileHandler appends a slash and redirects a request path beginning with two slashes, so browsers interpret the result as a protocol-relative URL whose first segment is an attacker-controlled host. Exploitation requires static_url_prefix set to /, any default_filename, knowledge of the absolute static-directory path, and a user who follows the crafted link.

CVSS severity5.3
Medium
EPSS probability1.14%
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 Tornado 6.3.1 and earlier allows remote attackers to send users to arbitrary sites through crafted URLs. StaticFileHandler appends a slash and redirects a request path beginning with two slashes, so browsers interpret the result as a protocol-relative URL whose first segment is an attacker-controlled host. Exploitation requires static_url_prefix set to /, any default_filename, knowledge of the absolute static-directory path, and a user who follows the crafted link.

The record

CVE
CVE-2023-28370
Published
May 25, 2023
Updated
Nov 3, 2025
Vendor
tornadoweb
Product
Tornado
Classifications
CWE-601, T1566.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 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=versions 6.3.1 and earlier

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

tornadoweb · Tornadoversion=versions 6.3.1 and earlier

Published CVSS scores

6.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.3GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
6.1NIST NVDCVSS: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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-601URL Redirection to Untrusted Site ('Open Redirect')
T1566.002Phishing: Spearphishing Link

Public exploit references

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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