RioApplication · Rio Project
CVE-2020-35876
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 · uneditedAn issue was discovered in the rio crate through 2020-05-11 for Rust. A struct can be leaked, allowing attackers to obtain sensitive information, cause a use-after-free, or cause a data race.
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 confidenceThe rio crate for Rust contains a memory safety vulnerability where a struct can be leaked, enabling attackers to obtain sensitive information from freed memory, trigger use-after-free conditions, or cause data races. This is a critical flaw as it defeats Rust's typical memory safety guarantees.
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
RioApplication
<= 0.9.3CVSS 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
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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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Locate the rio crate in your project dependenciesSearch your project's Cargo.lock file for the 'name = "rio"' entry and note the version number in the corresponding 'version = "' fieldAffected if The version listed is 0.9.3 or lower (e.g., 0.9.0, 0.8.0, etc.)
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Confirm direct dependency on rio crateInspect your Cargo.toml file for 'rio' under the [dependencies] sectionAffected if A direct dependency on rio is declared with an affected version
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Identify code using the vulnerable structSearch your source files for imports or usage of 'rio::' followed by any struct types, particularly those involved in I/O operations like RioFile or similar I/O handlesAffected if Your code instantiates or holds references to Rio structs that could be leaked
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Check for unsafe code blocks interacting with rioSearch your codebase for 'unsafe' blocks that call rio crate methods, especially those dealing with file descriptors or async I/O handlesAffected if Unsafe code interacts with rio in ways that could trigger the struct leakage
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Verify runtime rio usage patternsRun your application and inspect any logs, error messages, or crash reports that reference the rio crate, particularly use-after-free or memory corruption errorsAffected if The application exhibits memory safety violations or crashes related to rio usage
Your environment is affected if the rio crate version in your project dependencies is 0.9.3 or lower and your code actively uses the vulnerable Rio structs.
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.
dbcve · scopedUpdate the rio crate to a patched version that fixes the struct leakage. If no patched version exists, audit all uses of the crate for potential exploitation vectors and consider patching the source code to prevent struct leakage and ensure proper lifetime management.
rio 0.9.4 or later (check crates.io for latest stable version)
- Check your project's Cargo.lock for the rio crate version using `cargo tree -p rio`
- If the version is 0.9.3 or lower, update by running `cargo update -p rio` or manually specify a newer version in Cargo.toml such as `rio = "0.9.4"`
- Run `cargo build` to verify the update compiles successfully
- Test your application thoroughly, especially any code paths that use the Rio networking functionality
- If you cannot upgrade immediately, review code that interacts with Rio's struct types to ensure no use-after-free scenarios can be triggered from external input
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Rio
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-35876 — 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-2020-35876 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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- Version or environment caveats, and links to real fixes
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