CVE-2016-9843

The crc32_big function in crc32.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact via vectors involving big-endian CRC calculation.

Published: 2017-05-23 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-9843 is rated High Risk (66.5/100): CVSS Critical severity, with high exploitation likelihood (EPSS 6.00%, 92th 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-2016-9843

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 2026-06-15 17.67% 6.00% -11.68%
2 2026-06-14 13.50% 17.67% +4.17%
3 2026-06-06 — 13.50% —

Full EPSS history (27 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-9843

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/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:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2016-9843

OS Trackers for CVE-2016-9843

vendor priority summary link
alpine — CVE-2016-9843: 1 source package rows (mariadb); 10 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 0. https://security.alpinelinux.org/vuln/CVE-2016-9843
debian not yet assigned CVE-2016-9843 not yet assigned priority: Debian including 2 source packages (rsync, zlib), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10. https://security-tracker.debian.org/tracker/CVE-2016-9843
gentoo normal CVE-2016-9843: 2 GLSA(s) (201701-56, 202007-54), 2 atom(s) (net-misc/rsync, sys-libs/zlib); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-9843
redhat low — https://access.redhat.com/security/cve/CVE-2016-9843
suse medium CVE-2016-9843 severity moderate: SUSE including 638 source package names (0.9.1:libz1-1.2.8-11.1, 1.0.0:libz1-1.2.8-11.1, …), 1155 product×package rows across 134 product lines (Container caasp/v4/default-http-backend, Container caasp/v4/dnsmasq-nanny, … (134 product lines)): Fixed 940, Known Affected 157, Known Not Affected 58. https://www.suse.com/security/cve/CVE-2016-9843/
ubuntu low CVE-2016-9843 low priority: Ubuntu including 4 source packages (klibc, rsync, zlib, zsync), 61 status rows across 23 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, precise, questing, trusty, upstream, xenial, yakkety, zesty): released 26, not-affected 18, needs-triage 8, ignored 7, needed 2. https://ubuntu.com/security/CVE-2016-9843

Affected software / configurations for CVE-2016-9843

Vendor Product Version Raw CPE
zlib zlib >= 1.2.0, < 1.2.9 cpe:2.3:a:zlib:zlib:*:*:*:*:*:*:*:*
opensuse leap 42.1 cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:*
opensuse leap 42.2 cpe:2.3:o:opensuse:leap:42.2:*:*:*:*:*:*:*
opensuse opensuse 13.2 cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
oracle database_server 18c cpe:2.3:a:oracle:database_server:18c:*:*:*:*:*:*:*
oracle jdk 1.6.0 cpe:2.3:a:oracle:jdk:1.6.0:update161:*:*:*:*:*:*
oracle jdk 1.7.0 cpe:2.3:a:oracle:jdk:1.7.0:update151:*:*:*:*:*:*
oracle jdk 1.8.0 cpe:2.3:a:oracle:jdk:1.8.0:update144:*:*:*:*:*:*
oracle jre 1.6.0 cpe:2.3:a:oracle:jre:1.6.0:update161:*:*:*:*:*:*
oracle jre 1.7.0 cpe:2.3:a:oracle:jre:1.7.0:update151:*:*:*:*:*:*
oracle jre 1.8.0 cpe:2.3:a:oracle:jre:1.8.0:update144:*:*:*:*:*:*
oracle mysql >= 5.5.0, <= 5.5.61 cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*
oracle mysql >= 5.6.0, <= 5.6.41 cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*
oracle mysql >= 5.7.0, <= 5.7.23 cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*
oracle mysql >= 8.0.0, <= 8.0.12 cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*
redhat satellite 5.8 cpe:2.3:a:redhat:satellite:5.8:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 6.0 cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 7.0 cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_eus 7.4 cpe:2.3:o:redhat:enterprise_linux_eus:7.4:*:*:*:*:*:*:*
redhat enterprise_linux_eus 7.5 cpe:2.3:o:redhat:enterprise_linux_eus:7.5:*:*:*:*:*:*:*
redhat enterprise_linux_server 6.0 cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 7.0 cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 6.0 cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 7.0 cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
apple iphone_os < 11 cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple mac_os_x >= 10.0.0, < 10.13.0 cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
apple tvos < 11.0 cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
apple watchos < 4 cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
netapp active_iq_unified_manager >= 7.3 cpe:2.3:a:netapp:active_iq_unified_manager:*:*:*:*:*:windows:*:*
netapp active_iq_unified_manager >= 9.5 cpe:2.3:a:netapp:active_iq_unified_manager:*:*:*:*:*:vmware_vsphere:*:*
netapp oncommand_insight — cpe:2.3:a:netapp:oncommand_insight:-:*:*:*:*:*:*:*
netapp oncommand_workflow_automation — cpe:2.3:a:netapp:oncommand_workflow_automation:-:*:*:*:*:*:*:*
netapp snapcenter — cpe:2.3:a:netapp:snapcenter:-:*:*:*:*:*:*:*
mariadb mariadb >= 5.5.0, < 5.5.62 cpe:2.3:a:mariadb:mariadb:*:*:*:*:*:*:*:*
mariadb mariadb >= 10.0.0, < 10.0.37 cpe:2.3:a:mariadb:mariadb:*:*:*:*:*:*:*:*
mariadb mariadb >= 10.1.0, < 10.1.37 cpe:2.3:a:mariadb:mariadb:*:*:*:*:*:*:*:*
mariadb mariadb >= 10.2.0, < 10.2.19 cpe:2.3:a:mariadb:mariadb:*:*:*:*:*:*:*:*
mariadb mariadb >= 10.3.0, < 10.3.11 cpe:2.3:a:mariadb:mariadb:*:*:*:*:*:*:*:*
nodejs node.js >= 4.0.0, <= 4.1.2 cpe:2.3:a:nodejs:node.js:*:*:*:*:-:*:*:*
nodejs node.js >= 4.2.0, < 4.8.2 cpe:2.3:a:nodejs:node.js:*:*:*:*:lts:*:*:*
nodejs node.js >= 6.0.0, <= 6.8.1 cpe:2.3:a:nodejs:node.js:*:*:*:*:-:*:*:*
nodejs node.js >= 6.9.0, < 6.10.2 cpe:2.3:a:nodejs:node.js:*:*:*:*:lts:*:*:*
nodejs node.js >= 7.0.0, < 7.6.0 cpe:2.3:a:nodejs:node.js:*:*:*:*:-:*:*:*

References for CVE-2016-9843

URL Tags
http://lists.opensuse.org/opensuse-updates/2016-12/msg00127.html
http://lists.opensuse.org/opensuse-updates/2017-01/msg00050.html
http://lists.opensuse.org/opensuse-updates/2017-01/msg00053.html
http://www.openwall.com/lists/oss-security/2016/12/05/21
http://www.oracle.com/technetwork/security-advisory/cpujul2018-4258247.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
http://www.securityfocus.com/bid/95131
http://www.securitytracker.com/id/1039427
http://www.securitytracker.com/id/1041888
https://access.redhat.com/errata/RHSA-2017:1220
https://access.redhat.com/errata/RHSA-2017:1221
https://access.redhat.com/errata/RHSA-2017:1222
https://access.redhat.com/errata/RHSA-2017:2999
https://access.redhat.com/errata/RHSA-2017:3046
https://access.redhat.com/errata/RHSA-2017:3047
https://access.redhat.com/errata/RHSA-2017:3453
https://bugzilla.redhat.com/show_bug.cgi?id=1402351
https://github.com/madler/zlib/commit/d1d577490c15a0c6862473d7576352a9f18ef811
https://lists.debian.org/debian-lts-announce/2019/03/msg00027.html
https://lists.debian.org/debian-lts-announce/2020/01/msg00030.html
https://security.gentoo.org/glsa/201701-56
https://security.gentoo.org/glsa/202007-54
https://security.netapp.com/advisory/ntap-20181018-0002/
https://support.apple.com/HT208112
https://support.apple.com/HT208113
https://support.apple.com/HT208115
https://support.apple.com/HT208144
https://usn.ubuntu.com/4246-1/
https://usn.ubuntu.com/4292-1/
https://wiki.mozilla.org/MOSS/Secure_Open_Source/Completed#zlib
https://wiki.mozilla.org/images/0/09/Zlib-report.pdf
https://www.oracle.com/security-alerts/cpujul2020.html
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