ProxygenApplication · Facebook

CVE-2020-1897

CRITICAL · 9.8 CVSS v3.1 Published 2020-05-18
Fix available
A fix is available. Upgrade to 2020.05.18.00 or later.
See remediation →
100/100
Remediation priority · Urgent
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
A use-after-free is possible due to an error in lifetime management in the request adaptor when a malicious client invokes request error handling in a specific sequence. This issue affects versions of proxygen prior to v2020.05.18.00.

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 confidence

Use-after-free vulnerability in proxygen's request adaptor due to improper lifetime management when a malicious client triggers request error handling in a specific sequence. This memory corruption issue could allow remote code execution.

MitigationUpgrade proxygen to version v2020.05.18.00 or later which contains the corrected lifetime management in the request adaptor.

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
ProxygenApplication
Affected:< 2020.05.18.00

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
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 checks

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

  1. Identify proxygen library version
    Check the installed proxygen version by inspecting the library binary, package manager output, or version header file (typically in proxygen/VERSION or through the build system)
    Affected if version is below 2020.05.18.00
  2. Confirm proxygen is used as HTTP server
    Inspect the codebase or deployment configuration to verify proxygen is instantiated as an HTTP server accepting incoming connections (e.g., proxygen::HTTPServer or similar)
    Affected if proxygen is used to handle incoming HTTP requests from clients
  3. Verify exposure to untrusted network
    Review network configuration to determine if the proxygen server accepts connections from untrusted or unauthenticated clients (not limited to trusted internal networks)
    Affected if server accepts connections from untrusted or public-facing network sources

Affected if running proxygen version older than 2020.05.18.00 as an HTTP server exposed to untrusted clients who can trigger the request error handling sequence.

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 2020.05.18.00 or later
Fixed in 2020.05.18.00
Interim mitigation

Upgrade proxygen to version v2020.05.18.00 or later which contains the corrected lifetime management in the request adaptor.

Recommended fix High confidence

v2020.05.18.00

  1. Identify the current Proxygen version in use by checking build artifacts, dependencies, or running binaries
  2. Compare the current version against the vulnerable version range (all versions prior to v2020.05.18.00)
  3. Upgrade Proxygen to v2020.05.18.00 or later by updating the dependency in your build system (e.g., package manager, submodule, or vendored source)
  4. Rebuild and redeploy any services that depend on the updated Proxygen library
  5. Verify the upgrade was successful by confirming the new version is running and testing that the affected request adaptor functionality operates correctly

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

Fix this in Proxygen Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
20.0 hours of engineering $3,460
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,536.

Scan for this in your stack

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dbcve dependency scanner

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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-2020-1897 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