CVE-2019-11478 | SACK can cause extensive memory use via fragmented resend queue

Jonathan Looney discovered that the TCP retransmission queue implementation in tcp_fragment in the Linux kernel could be fragmented when handling certain TCP Selective Acknowledgment (SACK) sequences. 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 commit f070ef2ac66716357066b683fb0baf55f8191a2e.

Published: 2019-06-19 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-11478 is rated Moderate Risk (54.6/100): CVSS Medium severity, with high exploitation likelihood (EPSS 29.76%, 97th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2019-11478

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-03 30.13% 29.76% -0.37%
2 2025-12-28 23.79% 30.13% +6.35%
3 2025-12-27 — 23.79% —

Full EPSS history (36 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-11478

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.0 MEDIUM
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2019-11478

OS Trackers for CVE-2019-11478

vendor priority summary link
debian not yet assigned CVE-2019-11478 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-11478
redhat medium — https://access.redhat.com/security/cve/CVE-2019-11478
suse high CVE-2019-11478 severity important: SUSE including 783 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 1159 product×package rows across 105 product lines (SUSE CaaS Platform 3.0, SUSE Enterprise Storage 4, … (105 product lines)): Fixed 968, Known Affected 157, Known Not Affected 34. https://www.suse.com/security/cve/CVE-2019-11478/
ubuntu high CVE-2019-11478 high priority: Ubuntu including 92 source packages (linux, linux-aws, …), 856 status rows across 12 suites (bionic, cosmic, disco, eoan, focal, jammy, noble, oracular, plucky, trusty, upstream, xenial): DNE 570, released 139, not-affected 136, ignored 11. https://ubuntu.com/security/CVE-2019-11478

Affected software / configurations for CVE-2019-11478

Vendor Product Version Raw CPE
linux linux_kernel < 4.4.182 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.5, < 4.9.182 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.10, < 4.14.127 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.15, < 4.19.52 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.20, < 5.1.11 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager 15.0.0 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:15.0.0:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager 15.0.0 cpe:2.3:a:f5:big-ip_access_policy_manager:15.0.0:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager 15.0.0 cpe:2.3:a:f5:big-ip_application_acceleration_manager:15.0.0:*:*:*:*:*:*:*
f5 big-ip_link_controller >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_link_controller:*:*:*:*:*:*:*:*
f5 big-ip_link_controller >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_link_controller:*:*:*:*:*:*:*:*
f5 big-ip_link_controller >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_link_controller:*:*:*:*:*:*:*:*
f5 big-ip_link_controller >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_link_controller:*:*:*:*:*:*:*:*
f5 big-ip_link_controller 15.0.0 cpe:2.3:a:f5:big-ip_link_controller:15.0.0:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:*:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:*:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:*:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:*:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager 15.0.0 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:15.0.0:*:*:*:*:*:*:*
f5 big-ip_webaccelerator >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_webaccelerator:*:*:*:*:*:*:*:*
f5 big-ip_webaccelerator >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_webaccelerator:*:*:*:*:*:*:*:*
f5 big-ip_webaccelerator >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_webaccelerator:*:*:*:*:*:*:*:*
f5 big-ip_webaccelerator >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_webaccelerator:*:*:*:*:*:*:*:*
f5 big-ip_webaccelerator 15.0.0 cpe:2.3:a:f5:big-ip_webaccelerator:15.0.0:*:*:*:*:*:*:*
f5 big-ip_application_security_manager >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_security_manager >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_security_manager >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_security_manager >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_security_manager 15.0.0 cpe:2.3:a:f5:big-ip_application_security_manager:15.0.0:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_local_traffic_manager:*:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_local_traffic_manager:*:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_local_traffic_manager:*:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_local_traffic_manager:*:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager 15.0.0 cpe:2.3:a:f5:big-ip_local_traffic_manager:15.0.0:*:*:*:*:*:*:*
f5 big-ip_fraud_protection_service >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_fraud_protection_service:*:*:*:*:*:*:*:*
f5 big-ip_fraud_protection_service >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_fraud_protection_service:*:*:*:*:*:*:*:*
f5 big-ip_fraud_protection_service >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_fraud_protection_service:*:*:*:*:*:*:*:*
f5 big-ip_fraud_protection_service >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_fraud_protection_service:*:*:*:*:*:*:*:*
f5 big-ip_fraud_protection_service 15.0.0 cpe:2.3:a:f5:big-ip_fraud_protection_service:15.0.0:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_global_traffic_manager:*:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_global_traffic_manager:*:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_global_traffic_manager:*:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_global_traffic_manager:*:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager 15.0.0 cpe:2.3:a:f5:big-ip_global_traffic_manager:15.0.0:*:*:*:*:*:*:*
f5 big-ip_analytics >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
f5 big-ip_analytics >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
f5 big-ip_analytics >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
f5 big-ip_analytics >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
f5 big-ip_analytics 15.0.0 cpe:2.3:a:f5:big-ip_analytics:15.0.0:*:*:*:*:*:*:*
f5 big-ip_edge_gateway >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_edge_gateway:*:*:*:*:*:*:*:*
f5 big-ip_edge_gateway >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_edge_gateway:*:*:*:*:*:*:*:*
f5 big-ip_edge_gateway >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_edge_gateway:*:*:*:*:*:*:*:*
f5 big-ip_edge_gateway >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_edge_gateway:*:*:*:*:*:*:*:*
f5 big-ip_edge_gateway 15.0.0 cpe:2.3:a:f5:big-ip_edge_gateway:15.0.0:*:*:*:*:*:*:*
f5 big-ip_domain_name_system >= 11.5.2, <= 11.6.4 cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 big-ip_domain_name_system >= 12.1.0, <= 12.1.4 cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 big-ip_domain_name_system >= 13.1.0, <= 13.1.1 cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 big-ip_domain_name_system >= 14.0.0, <= 14.1.0 cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 big-ip_domain_name_system 15.0.0 cpe:2.3:a:f5:big-ip_domain_name_system:15.0.0:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.10 cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
canonical ubuntu_linux 19.04 cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:*
redhat enterprise_linux_atomic_host — cpe:2.3:a:redhat:enterprise_linux_atomic_host:-:*:*:*:*:*:*:*
redhat enterprise_linux 5.0 cpe:2.3:o:redhat:enterprise_linux:5.0:*:*:*:*:*:*:*
redhat enterprise_linux 6.0 cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*

References for CVE-2019-11478

URL Tags
http://packetstormsecurity.com/files/153346/Kernel-Live-Patch-Security-Notice-LSN-0052-1.html Third Party Advisory VDB Entry
http://packetstormsecurity.com/files/154408/Kernel-Live-Patch-Security-Notice-LSN-0055-1.html
http://packetstormsecurity.com/files/154951/Kernel-Live-Patch-Security-Notice-LSN-0058-1.html
http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2020-010.txt
http://www.openwall.com/lists/oss-security/2019/06/28/2
http://www.openwall.com/lists/oss-security/2019/07/06/3
http://www.openwall.com/lists/oss-security/2019/07/06/4
http://www.openwall.com/lists/oss-security/2019/10/24/1
http://www.openwall.com/lists/oss-security/2019/10/29/3
http://www.vmware.com/security/advisories/VMSA-2019-0010.html
https://access.redhat.com/errata/RHSA-2019:1594
https://access.redhat.com/errata/RHSA-2019:1602
https://access.redhat.com/errata/RHSA-2019:1699
https://access.redhat.com/security/vulnerabilities/tcpsack Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-462066.pdf
https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit/?id=f070ef2ac66716357066b683fb0baf55f8191a2e Mailing List Patch Vendor Advisory
https://github.com/Netflix/security-bulletins/blob/master/advisories/third-party/2019-001.md Patch Third Party Advisory
https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44193 Third Party Advisory
https://kc.mcafee.com/corporate/index?page=content&id=SB10287
https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2019-0007
https://seclists.org/bugtraq/2019/Jul/30
https://security.netapp.com/advisory/ntap-20190625-0001/
https://support.f5.com/csp/article/K26618426 Third Party Advisory
https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/SACKPanic Mitigation Third Party Advisory
https://www.kb.cert.org/vuls/id/905115
https://www.oracle.com/security-alerts/cpujan2020.html
https://www.oracle.com/security-alerts/cpuoct2020.html
https://www.synology.com/security/advisory/Synology_SA_19_28
https://www.us-cert.gov/ics/advisories/icsa-19-253-03
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