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GoApplication · Golang

CVE-2021-41771

HIGH · 7.5 CVSS v3.1 Published 2021-11-08
Fix available
A fix is available. Upgrade to 1.16.10 / 1.17.3 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
ImportedSymbols in debug/macho (for Open or OpenFat) in Go before 1.16.10 and 1.17.x before 1.17.3 Accesses a Memory Location After the End of a Buffer, aka an out-of-bounds slice situation.

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

Go's debug/macho package contains an out-of-bounds read vulnerability in the ImportedSymbols function (used by Open or OpenFat). When parsing malformed or crafted Mach-O binary files, the code accesses memory locations beyond the allocated buffer, potentially allowing attackers to read sensitive memory contents or cause denial of service.

MitigationUpgrade Go to version 1.16.10 or later (for 1.16.x branch) or 1.17.3 or later (for 1.17.x branch). Audit any custom code using debug/macho for similar issues.

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
GoApplication
Affected:< 1.16.10>= 1.17.0, < 1.17.3
FedoraOperating system
Affected:= 34= 35
Debian LinuxOperating system
Affected:= 9.0

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. Determine installed Go version
    Run 'go version' to see the Go compiler version, or check the Go installation directory for the version file
    Affected if Version is less than 1.16.10 (for 1.16.x branch) or greater than or equal to 1.17.0 but less than 1.17.3
  2. Identify code using debug/macho package
    Search source code for imports of 'debug/macho' or usage of macho.Open or macho.OpenFat functions
    Affected if The codebase imports or uses the debug/macho package to parse Mach-O files
  3. Check if Mach-O files from untrusted sources are processed
    Review code paths that call macho.Open or macho.OpenFat and determine the source of the Mach-O file data (user input, network, external files)
    Affected if Mach-O files from untrusted or external sources are processed by the vulnerable functions
  4. Verify Go binary package manager versions (if using modules)
    Run 'go list -m all' or check go.mod for the Go version directive
    Affected if The go.mod specifies a Go version affected by this CVE
  5. Audit Fedora or Debian system Go packages
    On affected distributions, check installed Go packages with 'rpm -qa | grep golang' (Fedora) or 'dpkg -l | grep golang' (Debian)
    Affected if Running Fedora 34/35 or Debian 9.0 with system-provided Go packages in affected versions

You are affected if your Go version falls within the vulnerable ranges (< 1.16.10 or >= 1.17.0 to < 1.17.3) AND your code uses debug/macho to parse Mach-O files from potentially untrusted sources.

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 1.16.10 / 1.17.3 or later
Fixed in 1.16.101.17.3
Interim mitigation

Upgrade Go to version 1.16.10 or later (for 1.16.x branch) or 1.17.3 or later (for 1.17.x branch). Audit any custom code using debug/macho for similar issues.

Recommended fix High confidence

Go 1.16.10 or Go 1.17.3 or later

  1. 1. Identify current Go version by running: go version
  2. 2. If running Go < 1.16.10, upgrade to Go 1.16.10 or later (1.17.x users should upgrade to 1.17.3 or later)
  3. 3. Download the appropriate Go installation package from https://golang.org/dl/
  4. 4. Remove the existing Go installation (e.g., rm -rf /usr/local/go)
  5. 5. Extract the new Go version to /usr/local/go
  6. 6. Ensure /usr/local/go/bin is in your PATH environment variable
  7. 7. Verify the upgrade: go version
Caveat Minor version upgrades within the same major Go release typically have minimal breaking changes; however, review the Go release notes for any behavior changes between your current version and the target fixed version.

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

Fix this in Go Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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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-2021-41771 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