CVE-2020-13121Public exploitNetwork attack vector

Phishing via unvalidated login return URL

Published May 16, 2020 · Updated Aug 4, 2024

Open redirect in Submitty 20.04.01 and earlier allows remote attackers to send users to an attacker-controlled site after an invalid login. AuthenticationController accepts the old query parameter as a return URL and redirects to it without restricting the destination to the Submitty domain. Exploitation requires a user to follow a crafted login link and submit invalid credentials, after which the redirect can support a phishing attempt.

CVSS severity6.1
Medium
EPSS probability2.93%
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 Submitty 20.04.01 and earlier allows remote attackers to send users to an attacker-controlled site after an invalid login. AuthenticationController accepts the old query parameter as a return URL and redirects to it without restricting the destination to the Submitty domain. Exploitation requires a user to follow a crafted login link and submit invalid credentials, after which the redirect can support a phishing attempt.

The record

CVE
CVE-2020-13121
Published
May 16, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-601, T1566.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 16, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A: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.

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

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')
T1566.002Spearphishing 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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