dbcve.org
FreeBSDOperating system

CVE-2020-7463

MEDIUM · 5.5 CVSS v3.1 Published 2021-03-26
Fix available
A fix is available. Upgrade to 11.3 / 12.3 or later.
See remediation →
57/100
Remediation priority · Elevated
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
In FreeBSD 12.1-STABLE before r364644, 11.4-STABLE before r364651, 12.1-RELEASE before p9, 11.4-RELEASE before p3, and 11.3-RELEASE before p13, improper handling in the kernel causes a use-after-free bug by sending large user messages from multiple threads on the same SCTP socket. The use-after-free situation may result in unintended kernel behaviour including a kernel panic.

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 the FreeBSD kernel's SCTP socket implementation where improper handling of large user messages from multiple threads on the same SCTP socket leads to dangling pointer dereference, potentially causing kernel panic.

MitigationApply vendor patches (FreeBSD stable RELENG_12_1 r364644, stable RELENG_11_4 r364651, or respective release patches p9/p3/p13) to address the memory management flaw in SCTP message handling.

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
FreeBSDOperating system
Affected:= 11.3= 11.4= 12.1= 12.2
SafariWeb browser
Affected:< 14.1
IcloudApplication
Affected:< 12.3
ItunesApplication
Affected:< 12.11.3
IpadosOperating system
Affected:< 14.5
Iphone OsOperating system
Affected:< 14.5
macOSOperating system
Affected:>= 11.0, < 11.3
TvosOperating system
Affected:< 14.5

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/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. Check FreeBSD kernel version
    Run `uname -r` to obtain the kernel release version
    Affected if The version matches 11.3, 11.4, 12.1, or 12.2 (e.g., 12.1-RELEASE, 12.2-RELEASE-pX)
  2. Verify SCTP kernel module is loaded
    Run `kldstat | grep -i sctp` or check `sysctl net.inet.sctp.enable`
    Affected if SCTP is loaded or enabled (output shows sctp module or net.inet.sctp.enable = 1)
  3. Identify active SCTP sockets
    Run `netstat -sctp` or `sockstat -sctp` to list SCTP connections and listeners
    Affected if There are active SCTP sockets (established connections or listening ports)
  4. Detect multi-threaded SCTP usage
    Examine process usage of SCTP sockets via `sockstat | grep sctp` and check if multiple threads access the same socket
    Affected if Multiple threads from the same process are using SCTP sockets, especially with large message payloads

You are affected if running FreeBSD 11.3-12.2 with SCTP enabled and actively used by multi-threaded applications handling large messages.

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.

From vendor data
Upgrade available Upgrade to 11.3 / 12.3 / 12.11.3 or later
Fixed in 11.312.312.11.3
Interim mitigation

Apply vendor patches (FreeBSD stable RELENG_12_1 r364644, stable RELENG_11_4 r364651, or respective release patches p9/p3/p13) to address the memory management flaw in SCTP message handling.

Fix this in FreeBSD Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-7463 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2020-7463 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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