CVE-2021-34254
CVE-2021-34254 is a medium-severity vulnerability in Umbraco Umbraco Cms with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-601.
Key facts
- Severity: Medium (CVSS 3.x base score 6.1)
- CVSS v2: 5.8
- EPSS exploit prediction: 1% (49th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-601
- Affected product: Umbraco Umbraco Cms
- Published:
- Last modified:
Description
Umbraco CMS before 7.15.7 is vulnerable to Open Redirection due to insufficient url sanitization on booting.aspx.
Frequently asked questions
- What is CVE-2021-34254?
- Umbraco CMS before 7.15.7 is vulnerable to Open Redirection due to insufficient url sanitization on booting.aspx.
- How severe is CVE-2021-34254?
- CVE-2021-34254 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
- Is CVE-2021-34254 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-34254?
- CVE-2021-34254 affects Umbraco Umbraco Cms. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-34254?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2021-34254 published?
- CVE-2021-34254 was published on 2021-06-28 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:umbraco:umbraco_cms:*:*:*:*:*:*:*:*
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Other CWE-601 (Open Redirect) vulnerabilities
- CVE-2018-3774 — Critical (CVSS 10.0): Incorrect parsing in url-parse <1.4.3 returns wrong hostname which leads to multiple vulnerabilities such as SSRF, Open…
- CVE-2019-25282 — Critical (CVSS 9.8): V-SOL GPON/EPON OLT Platform v2.03 contains an open redirect vulnerability in the script that allows attackers to…
- CVE-2020-36912 — Critical (CVSS 9.8): Plexus anblick Digital Signage Management 3.1.13 contains an open redirect vulnerability in the 'PantallaLogin' script…
- CVE-2025-43526 — Critical (CVSS 9.8): This issue was addressed with improved URL validation. This issue is fixed in Safari 26.2, macOS Tahoe 26.2. On a Mac…
- CVE-2025-55031 — Critical (CVSS 9.8): Malicious pages could use Firefox for iOS to pass FIDO: links to the OS and trigger the hybrid passkey transport. An…
- CVE-2024-22891 — Critical (CVSS 9.8): Nteract v.0.28.0 was discovered to contain a remote code execution (RCE) vulnerability via the Markdown link.