CVE-2016-5696

Exp

net/ipv4/tcp_input.c in the Linux kernel before 4.7 does not properly determine the rate of challenge ACK segments, which makes it easier for remote attackers to hijack TCP sessions via a blind in-window attack.

Published: 2016-08-06 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-5696 is rated High Exploit Risk (73.5/100): CVSS Medium severity, with high exploitation likelihood (EPSS 51.99%, 98th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +22.83% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2016-5696

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2016-5696

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 2026-04-18 29.16% 51.99% +22.83%
2 2026-04-01 33.30% 29.16% -4.14%
3 2026-02-20 — 33.30% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-5696

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.8 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.2 2.5 [email protected]
5.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 4.9 [email protected]

Weakness enumeration for CVE-2016-5696

OS Trackers for CVE-2016-5696

vendor priority summary link
debian not yet assigned CVE-2016-5696 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-2016-5696
redhat high — https://access.redhat.com/security/cve/CVE-2016-5696
suse medium CVE-2016-5696 severity moderate: SUSE including 159 source package names (kernel-bigmem-3.0.101-94.1, kernel-bigmem-base-3.0.101-94.1, …), 548 product×package rows across 87 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (87 product lines)): Fixed 290, Known Not Affected 258. https://www.suse.com/security/cve/CVE-2016-5696/
ubuntu medium CVE-2016-5696 medium priority: Ubuntu including 27 source packages (linux, linux-armadaxp, …), 185 status rows across 7 suites (precise, trusty, upstream, wily, xenial, yakkety, zesty): DNE 120, released 37, not-affected 15, ignored 13. https://ubuntu.com/security/CVE-2016-5696

Affected software / configurations for CVE-2016-5696

Vendor Product Version Raw CPE
google android <= 7.0 cpe:2.3:o:google:android:*:*:*:*:*:*:*:*
oracle vm_server 3.3 cpe:2.3:a:oracle:vm_server:3.3:*:*:*:*:*:*:*
oracle vm_server 3.4 cpe:2.3:a:oracle:vm_server:3.4:*:*:*:*:*:*:*
linux linux_kernel <= 4.6.6 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

References for CVE-2016-5696

URL Tags
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=75ff39ccc1bd5d3c455b6822ab09e533c551f758 Issue Tracking Patch
http://rhn.redhat.com/errata/RHSA-2016-1631.html
http://rhn.redhat.com/errata/RHSA-2016-1632.html
http://rhn.redhat.com/errata/RHSA-2016-1633.html
http://rhn.redhat.com/errata/RHSA-2016-1657.html
http://rhn.redhat.com/errata/RHSA-2016-1664.html
http://rhn.redhat.com/errata/RHSA-2016-1814.html
http://rhn.redhat.com/errata/RHSA-2016-1815.html
http://rhn.redhat.com/errata/RHSA-2016-1939.html
http://source.android.com/security/bulletin/2016-10-01.html Third Party Advisory
http://www.openwall.com/lists/oss-security/2016/07/12/2 Mailing List Third Party Advisory
http://www.oracle.com/technetwork/topics/security/linuxbulletinjul2016-3090544.html Third Party Advisory
http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html Vendor Advisory
http://www.prnewswire.com/news-releases/mitnick-attack-reappears-at-geekpwn-macau-contest-300270779.html Technical Description
http://www.securityfocus.com/bid/91704
http://www.securitytracker.com/id/1036625
http://www.ubuntu.com/usn/USN-3070-1
http://www.ubuntu.com/usn/USN-3070-2
http://www.ubuntu.com/usn/USN-3070-3
http://www.ubuntu.com/usn/USN-3070-4
http://www.ubuntu.com/usn/USN-3071-1
http://www.ubuntu.com/usn/USN-3071-2
http://www.ubuntu.com/usn/USN-3072-1
http://www.ubuntu.com/usn/USN-3072-2
https://bto.bluecoat.com/security-advisory/sa131
https://bugzilla.redhat.com/show_bug.cgi?id=1354708 Issue Tracking
https://github.com/Gnoxter/mountain_goat Exploit Third Party Advisory
https://github.com/torvalds/linux/commit/75ff39ccc1bd5d3c455b6822ab09e533c551f758 Issue Tracking Patch
https://kc.mcafee.com/corporate/index?page=content&id=SB10167
https://security.paloaltonetworks.com/CVE-2016-5696
https://www.arista.com/en/support/advisories-notices/security-advisories/1461-security-advisory-23
https://www.usenix.org/system/files/conference/usenixsecurity16/sec16_paper_cao.pdf Technical Description
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