CVE-2018-10844

It was found that the GnuTLS implementation of HMAC-SHA-256 was vulnerable to a Lucky thirteen style attack. Remote attackers could use this flaw to conduct distinguishing attacks and plaintext-recovery attacks via statistical analysis of timing data using crafted packets.

Published: 2018-08-22 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2018-10844 is rated Moderate Risk (57.8/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.62%). Core evidence: EPSS rose +3.37% over the last day, indicating growing attacker interest. Mandatory action: Review affected assets and schedule 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-2018-10844

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 0.25% 3.62% +3.37%
2 2026-05-14 0.19% 0.25% +0.06%
3 2025-11-21 0.19%

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-10844

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N 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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.2 3.6 [email protected]
5.9 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N 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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N 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:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
8.6 2.9 [email protected]

Weakness enumeration for CVE-2018-10844

OS Trackers for CVE-2018-10844

vendor priority summary link
alpine medium CVE-2018-10844: 1 source package rows (gnutls); 10 state rows across 5 repos (3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 0, open 10. https://security.alpinelinux.org/vuln/CVE-2018-10844
debian not yet assigned CVE-2018-10844 not yet assigned priority: Debian including 1 source packages (gnutls28), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-10844
redhat medium https://access.redhat.com/security/cve/CVE-2018-10844
suse medium CVE-2018-10844 severity moderate: SUSE including 375 source package names (0.1.0:libgnutls30-3.6.2-6.3.1, 0.1.75:libgnutls30-3.6.2-6.3.1, …), 488 product×package rows across 102 product lines (Container caasp/v4/389-ds, Container caasp/v4/busybox, … (102 product lines)): Fixed 318, Known Affected 157, Known Not Affected 13. https://www.suse.com/security/cve/CVE-2018-10844/
ubuntu medium CVE-2018-10844 medium priority: Ubuntu including 2 source packages (gnutls26, gnutls28), 38 status rows across 19 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 18, not-affected 15, released 3, needed 1, needs-triage 1. https://ubuntu.com/security/CVE-2018-10844

Affected software / configurations for CVE-2018-10844

Vendor Product Version Raw CPE
gnu gnutls < 3.6.12 cpe:2.3:a:gnu:gnutls:*:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 7.0 cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 7.0 cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 7.0 cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
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:*:*:*:*:*:*:*
fedoraproject fedora 31 cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*

References for CVE-2018-10844

URL Tags
http://www.securityfocus.com/bid/105138 Third Party Advisory VDB Entry
https://access.redhat.com/errata/RHSA-2018:3050 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3505 Broken Link
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10844 Issue Tracking Patch Third Party Advisory
https://eprint.iacr.org/2018/747 Third Party Advisory
https://gitlab.com/gnutls/gnutls/merge_requests/657 Issue Tracking Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/10/msg00022.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ILMOWPKMTZAIMK5F32TUMO34XCABUCFJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WDYY3R4F5CUTFAMXH2C5NKYFVDEJLTT7/
https://usn.ubuntu.com/3999-1/ Third Party Advisory
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