CVE-2016-6313

The mixing functions in the random number generator in Libgcrypt before 1.5.6, 1.6.x before 1.6.6, and 1.7.x before 1.7.3 and GnuPG before 1.4.21 make it easier for attackers to obtain the values of 160 bits by leveraging knowledge of the previous 4640 bits.

Published: 2016-12-13 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-6313 is rated Moderate Risk (50.8/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.69%). 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-2016-6313

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 2026-05-13 3.18% 2.69% -0.49%
2 2026-02-19 3.26% 3.18% -0.09%
3 2026-02-18 — 3.26% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-6313

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:L/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: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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/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:L)
Exploitation conditions are straightforward and predictable.
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.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2016-6313

OS Trackers for CVE-2016-6313

vendor priority summary link
debian unimportant CVE-2016-6313 unimportant priority: Debian including 3 source packages (gnupg1, gnupg2, libgcrypt20), 15 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 15. https://security-tracker.debian.org/tracker/CVE-2016-6313
gentoo normal CVE-2016-6313: 2 GLSA(s) (201610-04, 201612-01), 2 atom(s) (app-crypt/gnupg, dev-libs/libgcrypt); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-6313
redhat medium — https://access.redhat.com/security/cve/CVE-2016-6313
suse medium CVE-2016-6313 severity moderate: SUSE including 327 source package names (0.9.1:libgcrypt20-1.6.1-16.33.1, 1.0.0:libgcrypt20-1.6.1-16.33.1, …), 402 product×package rows across 87 product lines (Container caasp/v4/default-http-backend, Container caasp/v4/dnsmasq-nanny, … (87 product lines)): Fixed 244, Known Affected 157, Known Not Affected 1. https://www.suse.com/security/cve/CVE-2016-6313/
ubuntu high CVE-2016-6313 high priority: Ubuntu including 4 source packages (gnupg, gnupg2, libgcrypt11, libgcrypt20), 40 status rows across 10 suites (artful, bionic, cosmic, disco, precise, trusty, upstream, xenial, yakkety, zesty): DNE 16, released 15, not-affected 8, needs-triage 1. https://ubuntu.com/security/CVE-2016-6313

Affected software / configurations for CVE-2016-6313

Vendor Product Version Raw CPE
gnupg libgcrypt <= 1.5.3 cpe:2.3:a:gnupg:libgcrypt:*:*:*:*:*:*:*:*
gnupg libgcrypt 1.6.0 cpe:2.3:a:gnupg:libgcrypt:1.6.0:*:*:*:*:*:*:*
gnupg libgcrypt 1.6.1 cpe:2.3:a:gnupg:libgcrypt:1.6.1:*:*:*:*:*:*:*
gnupg libgcrypt 1.6.2 cpe:2.3:a:gnupg:libgcrypt:1.6.2:*:*:*:*:*:*:*
gnupg libgcrypt 1.6.3 cpe:2.3:a:gnupg:libgcrypt:1.6.3:*:*:*:*:*:*:*
gnupg libgcrypt 1.6.4 cpe:2.3:a:gnupg:libgcrypt:1.6.4:*:*:*:*:*:*:*
gnupg libgcrypt 1.6.5 cpe:2.3:a:gnupg:libgcrypt:1.6.5:*:*:*:*:*:*:*
gnupg libgcrypt 1.7.0 cpe:2.3:a:gnupg:libgcrypt:1.7.0:*:*:*:*:*:*:*
gnupg libgcrypt 1.7.1 cpe:2.3:a:gnupg:libgcrypt:1.7.1:*:*:*:*:*:*:*
gnupg libgcrypt 1.7.2 cpe:2.3:a:gnupg:libgcrypt:1.7.2:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
gnupg gnupg <= 1.4.14 cpe:2.3:a:gnupg:gnupg:*:*:*:*:*:*:*:*

References for CVE-2016-6313

cvelogic Threat Intelligence