CVE-2019-11479
Jonathan Looney discovered that the Linux kernel default MSS is hard-coded to 48 bytes.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 91.7%, higher than 100% of all known CVEs. Patch or mitigate before the next change window.
Description
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 91.66% probability · 100th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-405, CWE-770
- Affected
- linux/linux kernel · f5/big-ip advanced firewall manager · f5/big-ip access policy manager · f5/big-ip application acceleration manager · f5/big-ip link controller · f5/big-ip policy enforcement manager · f5/big-ip webaccelerator · f5/big-ip application security manager · f5/big-ip local traffic manager · f5/big-ip fraud protection service · f5/big-ip global traffic manager · f5/big-ip analytics · f5/big-ip edge gateway · f5/big-ip domain name system · canonical/ubuntu linux · redhat/enterprise linux · f5/big-iq centralized management · f5/enterprise manager · f5/iworkflow · f5/traffix signaling delivery controller · +1 more
- Source
- security@ubuntu.com
EPSS 91.7% since 27 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2020-010.txtThird Party Advisory
- http://www.openwall.com/lists/oss-security/2019/06/28/2Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2019/07/06/3Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2019/07/06/4Mailing List, Third Party Advisory
- http://www.securityfocus.com/bid/108818Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2019:1594Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:1602Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:1699Third Party Advisory
- https://access.redhat.com/security/vulnerabilities/tcpsackThird Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-462066.pdfThird Party Advisory
- https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit/?id=5f3e2bf008c2221478101ee72f5cb4654b9fc363Mailing List, Patch, Vendor Advisory
- https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit/?id=967c05aee439e6e5d7d805e195b3a20ef5c433d6Mailing List, Patch, Vendor Advisory
- https://github.com/Netflix/security-bulletins/blob/master/advisories/third-party/2019-001.mdPatch, Third Party Advisory
- https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44193Third Party Advisory
- https://kc.mcafee.com/corporate/index?page=content&id=SB10287Third Party Advisory
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2019-0008Third Party Advisory
- https://security.netapp.com/advisory/ntap-20190625-0001/Third Party Advisory
- https://support.f5.com/csp/article/K35421172Third Party Advisory
- https://support.f5.com/csp/article/K35421172?utm_source=f5support&%3Butm_medium=RSS
- https://usn.ubuntu.com/4041-1/Third Party Advisory
- https://usn.ubuntu.com/4041-2/Third Party Advisory
- https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/SACKPanicMitigation, Third Party Advisory
- https://www.kb.cert.org/vuls/id/905115Third Party Advisory, US Government Resource
- https://www.oracle.com/security-alerts/cpujan2020.htmlThird Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2020.html
- https://www.synology.com/security/advisory/Synology_SA_19_28Third Party Advisory
- https://www.us-cert.gov/ics/advisories/icsa-19-253-03Third Party Advisory, US Government Resource
- https://www.us-cert.gov/ics/advisories/icsma-20-170-06Third Party Advisory, US Government Resource
- http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2020-010.txtThird Party Advisory
- http://www.openwall.com/lists/oss-security/2019/06/28/2Mailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.