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Linux KernelOperating system · Linux

CVE-2019-11479

HIGH · 7.5 CVSS v3.1 Published 2019-06-19
Fix available
A fix is available. Upgrade to 4.4.182 / 4.9.182 or later.
See remediation →
84/100
Remediation priority · High
High EPSS Remotely reachable No privileges Zero-click Patch available

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
Jonathan Looney discovered that the Linux kernel default MSS is hard-coded to 48 bytes. This allows a remote peer to fragment TCP resend queues significantly more than if a larger MSS were enforced. A remote attacker could use this to cause a denial of service. This has been fixed in stable kernel releases 4.4.182, 4.9.182, 4.14.127, 4.19.52, 5.1.11, and is fixed in commits 967c05aee439e6e5d7d805e195b3a20ef5c433d6 and 5f3e2bf008c2221478101ee72f5cb4654b9fc363.

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

A detailed technical summary for this CVE is being prepared.

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
Linux KernelOperating system
Affected:>= 4.4, < 4.4.182>= 4.9, < 4.9.182>= 4.14, < 4.14.127>= 4.19, < 4.19.52>= 5.1, < 5.1.11
Big Ip Advanced Firewall ManagerApplication
Affected:>= 11.5.2, < 11.6.5.1>= 12.1.0, < 12.1.5.1>= 13.1.0, < 13.1.3.2>= 14.0.0, < 14.0.1.1>= 14.1.2, < 14.1.2.1>= 15.0.0, < 15.0.1.1
Big Ip Access Policy ManagerApplication
Affected:>= 11.5.2, < 11.6.5.1>= 12.1.0, < 12.1.5.1>= 13.1.0, < 13.1.3.2>= 14.0.0, < 14.0.1.1>= 14.1.2, < 14.1.2.1>= 15.0.0, < 15.0.1.1
Big Ip Application Acceleration ManagerApplication
Affected:>= 11.5.2, < 11.6.5.1>= 12.1.0, < 12.1.5.1>= 13.1.0, < 13.1.3.2>= 14.0.0, < 14.0.1.1>= 14.1.2, < 14.1.2.1>= 15.0.0, < 15.0.1.1
Big Ip Link ControllerApplication
Affected:>= 11.5.2, < 11.6.5.1>= 12.1.0, < 12.1.5.1>= 13.1.0, < 13.1.3.2>= 14.0.0, < 14.0.1.1>= 14.1.2, < 14.1.2.1>= 15.0.0, < 15.0.1.1
Big Ip Policy Enforcement ManagerApplication
Affected:>= 11.5.2, < 11.6.5.1>= 12.1.0, < 12.1.5.1>= 13.1.0, < 13.1.3.2>= 14.0.0, < 14.0.1.1>= 14.1.2, < 14.1.2.1>= 15.0.0, < 15.0.1.1
Big Ip WebacceleratorApplication
Affected:>= 11.5.2, < 11.6.5.1>= 12.1.0, < 12.1.5.1>= 13.1.0, < 13.1.3.2>= 14.0.0, < 14.0.1.1>= 14.1.2, < 14.1.2.1>= 15.0.0, < 15.0.1.1
Big Ip Application Security ManagerApplication
Affected:>= 11.5.2, < 11.6.5.1>= 12.1.0, < 12.1.5.1>= 13.1.0, < 13.1.3.2>= 14.0.0, < 14.0.1.1>= 14.1.2, < 14.1.2.1>= 15.0.0, < 15.0.1.1

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

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 4.4.182 / 4.9.182 / 4.14.127 or later
Fixed in 4.4.1824.9.1824.14.127
Vendor patch git.kernel.org →
We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

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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-2019-11479 in production — separate from our analysis above.

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