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UserverApplication

CVE-2022-28229

HIGH · 7.5 CVSS v3.1 Published 2022-12-23
Fix available
A fix is available. Upgrade to 2022-11-18 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
The hash functionality in userver before 42059b6319661583b3080cab9b595d4f8ac48128 allows attackers to cause a denial of service via crafted HTTP request, involving collisions.

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 confidence

The hash functionality in userver prior to commit 42059b6319661583b3080cab9b595d4f8ac48128 is vulnerable to hash collision attacks. Attackers can cause denial of service by sending crafted HTTP requests that trigger pathological hash collisions, leading to excessive CPU consumption and service unavailability.

MitigationUpgrade userver to version 42059b6319661583b3080cab9b595d4f8ac48128 or later, which implements proper hash randomization to prevent collision-based DoS attacks.

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
UserverApplication
Affected:< 2022-11-18

CVSS 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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify if userver is deployed
    Search for userver binaries, libraries, or look for userver-specific process names in running processes. Check build artifacts or dependency lists for userver packages.
    Affected if Userver is present in the environment and the version is < 2022-11-18 (or predates commit 42059b6319661583b3080cab9b595d4f8ac48128)
  2. Determine installed userver version
    Query the userver library or binary version using --version flags, checking library metadata, build info, or examining the git commit hash if accessible from build artifacts. Compare against the 2022-11-18 threshold.
    Affected if The version or commit date is earlier than 2022-11-18 (or commit 42059b6319661583b3080cab9b595d4f8ac48128)
  3. Verify HTTP server component is enabled
    Inspect the userver configuration files or startup parameters to confirm the HTTP server component (handlers, server) is actively enabled and listening for incoming requests.
    Affected if HTTP server is enabled and exposed to network traffic, providing the attack surface for collision-triggering requests
  4. Monitor for hash-related CPU spikes
    Review application logs and system metrics for unusual CPU consumption patterns, particularly in request processing threads, that could indicate active hash collision attacks.
    Affected if High CPU usage is observed in request handling paths without corresponding legitimate traffic load

The environment is affected if userver version is earlier than 2022-11-18 and the HTTP server component is enabled, exposing the service to hash collision DoS attacks via crafted HTTP requests.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 2022-11-18 or later
Fixed in 2022-11-18
Interim mitigation

Upgrade userver to version 42059b6319661583b3080cab9b595d4f8ac48128 or later, which implements proper hash randomization to prevent collision-based DoS attacks.

Recommended fix Moderate confidence

userver version 2022-11-18 or later

  1. 1. Identify the current userver version in use by checking the project's dependencies or built binaries
  2. 2. Update the userver dependency to version 2022-11-18 or later in your package manager/build system
  3. 3. Rebuild and redeploy the application with the updated userver library
  4. 4. Test the application to ensure normal functionality after the update
  5. 5. Verify that the hash collision attack vector is mitigated by confirming the new hash function implementation is in use

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Userver Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA4.0 h
20.0 hours of engineering $3,440
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,504.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-28229 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data