CVE-2016-2070

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2016-05-02 · updated 2026-06-17
Weakness: CWE-189

Description

The tcp_cwnd_reduction function in net/ipv4/tcp_input.c in the Linux kernel before 4.3.5 allows remote attackers to cause a denial of service (divide-by-zero error and system crash) via crafted TCP traffic.

Affected products

Linux kernel: from 4.3 before 4.3.5 — fixed in 4.3.5

How to fix

Upgrade to a fixed version: Linux kernel 4.3.5. Check the vendor advisory for mitigations.

References

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8b8a321ff72c785ed5e8b4cf6eda20b35d427390
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.3.5
http://www.openwall.com/lists/oss-security/2016/01/25/5
https://bugzilla.redhat.com/show_bug.cgi?id=1302219
https://github.com/torvalds/linux/commit/8b8a321ff72c785ed5e8b4cf6eda20b35d427390
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8b8a321ff72c785ed5e8b4cf6eda20b35d427390
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.3.5
http://www.openwall.com/lists/oss-security/2016/01/25/5
https://bugzilla.redhat.com/show_bug.cgi?id=1302219
https://github.com/torvalds/linux/commit/8b8a321ff72c785ed5e8b4cf6eda20b35d427390

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