CVE-2021-35206Public exploitNetwork attack vector

User redirection via unchecked authentication returnTo parameter

Published Jun 22, 2021 · Updated Aug 4, 2024

Open redirect in Gitpod before 0.6.0 allows remote attackers to send users to an attacker-chosen site through a crafted login URL. The server UserController passed the redirect or returnTo query value into authentication and authorization flows without first replacing it with the existing safe-return calculation. No account is required to create the link, but a user must follow it; the direct effect is navigation to an untrusted site rather than server compromise.

CVSS severity6.1
Medium
EPSS probability1.18%
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 Gitpod before 0.6.0 allows remote attackers to send users to an attacker-chosen site through a crafted login URL. The server UserController passed the redirect or returnTo query value into authentication and authorization flows without first replacing it with the existing safe-return calculation. No account is required to create the link, but a user must follow it; the direct effect is navigation to an untrusted site rather than server compromise.

The record

CVE
CVE-2021-35206
Published
Jun 22, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-601, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 22, 2021CVE 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')
T1204.001User Execution: Malicious 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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