CVE-2020-7949
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 · uneditedschemasystem.dll in Valve Dota 2 before 7.23f allows remote attackers to achieve code execution or denial of service by creating a gaming server and inviting a victim to this server, because a crafted map is mishandled during a GetValue call.
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 · moderate confidenceA vulnerability in schemasystem.dll in Valve Dota 2 before version 7.23f allows remote attackers to execute code or cause denial of service by hosting a game server with a crafted malicious map. When the victim joins the server, the map is parsed during a GetValue call, which mishandles the crafted data leading to exploitation.
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< 7.23fCVSS 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
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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 installed Dota 2 versionOpen the Dota 2 client and navigate to the game menu or version information. Alternatively, check the game files through Steam library properties or the console command 'version' in-game.Affected if The displayed version number is lower than 7.23f
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Verify schemasystem.dll file versionLocate schemasystem.dll in the Dota 2 game directory (typically in the 'game/dota/bin' or 'game/bin' folder) and check its file properties to view the version information.Affected if The DLL file version corresponds to a Dota 2 build earlier than 7.23f
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Confirm custom game server exposureDetermine if the user has joined or intends to join untrusted or unknown custom game servers (Arcade mode, custom lobbies from strangers).Affected if The user joins untrusted custom game servers while running a vulnerable Dota 2 version
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Identify GetValue call trigger conditionThis vulnerability is triggered during map loading when joining a malicious custom game server. The victim must connect to a server hosting a crafted map for exploitation.Affected if The user connects to a malicious custom game server while running a version below 7.23f
A user is affected if their installed Dota 2 client version is earlier than 7.23f and they join untrusted custom game servers.
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 data7.23f
Update Dota 2 to version 7.23f or later to patch the schemasystem.dll vulnerability. Users should avoid joining untrusted custom game servers until their client is updated.
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-7949 — 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-2020-7949 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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