CVE-2021-22970
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedConcrete CMS (formerly concrete5) versions 8.5.6 and below and version 9.0.0 allow local IP importing causing the system to be vulnerable toa. SSRF attacks on the private LAN servers by reading files from the local LAN. An attacker can pivot in the private LAN and exploit local network appsandb. SSRF Mitigation Bypass through DNS RebindingConcrete CMS security team gave this a CVSS score of 3.5 AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:NConcrete CMS is maintaining Concrete version 8.5.x until 1 May 2022 for security fixes.This CVE is shared with HackerOne Reports https://hackerone.com/reports/1364797 and https://hackerone.com/reports/1360016Reporters: Adrian Tiron from FORTBRIDGE (https://www.fortbridge.co.uk/ ) and Bipul Jaiswal
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceConcrete CMS versions 8.5.6 and below and 9.0.0 contain an SSRF vulnerability allowing local IP importing that enables attackers to make the server perform requests to internal network resources. This can be exploited to read files from local LAN servers and bypass SSRF mitigations through DNS rebinding techniques.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 8.5.6= 9.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check Concrete CMS installed versionLocate the version number in your Concrete CMS installation (typically in the dashboard under 'Dashboard > System & Settings > Update' or in a version file in the installation directory)Affected if The installed version is 8.5.6 or lower, or exactly 9.0.0
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Identify if URL importing feature is accessibleDetermine if any user role has access to features that accept external URLs for content import or fetching remote resources (such as XML sitemap import, feed importers, or similar URL-based import tools)Affected if Users with import permissions can supply arbitrary URLs including internal/local network addresses
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Verify network exposure to internal resourcesInspect server network configuration and firewall rules to determine if the Concrete CMS server can initiate connections to internal IP ranges (127.0.0.0/8, 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)Affected if The server can make HTTP requests to internal network addresses without restriction
You are affected if running Concrete CMS version 8.5.6 or below (or exactly 9.0.0) AND the URL importing feature is accessible to potentially malicious users AND the server has network access to internal resources.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpdate Concrete CMS to the latest patched version beyond 8.5.6/9.0.0. For version 8.5.x, security support is maintained until May 1, 2022. Implement network segmentation and restrict internal service access as a defense-in-depth measure.
- Consultation3.0 h
- Implementation6.0 h
- Testing6.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-22970 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-22970 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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