CVE-2016-7970

Buffer overflow in the calc_coeff function in libass/ass_blur.c in libass before 0.13.4 allows remote attackers to cause a denial of service via unspecified vectors.

Published: 2017-03-03 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-7970 is rated Moderate Risk (57.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.31%). 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-2016-7970

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 2026-01-25 1.24% 1.31% +0.07%
2 2025-03-30 1.67% 1.24% -0.43%
3 2025-03-29 — 1.67% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-7970

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/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:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2016-7970

OS Trackers for CVE-2016-7970

vendor priority summary link
alpine — CVE-2016-7970: 1 source package rows (libass); 9 state rows across 9 repos (3.10-main, 3.11-main, 3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 9, open 0. https://security.alpinelinux.org/vuln/CVE-2016-7970
debian not yet assigned CVE-2016-7970 not yet assigned priority: Debian including 1 source packages (libass), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2016-7970
gentoo normal CVE-2016-7970: 1 GLSA(s) (201702-25), 1 atom(s) (media-libs/libass); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-7970
suse medium CVE-2016-7970 severity moderate: SUSE including 18 source package names (libass-devel-0.10.2-3.1, libass-devel-0.13.4-2.1, …), 34 product×package rows across 24 product lines (SUSE Linux Enterprise Desktop 12 SP1, SUSE Linux Enterprise Desktop 12 SP2, … (24 product lines)): Fixed 34. https://www.suse.com/security/cve/CVE-2016-7970/
ubuntu medium CVE-2016-7970 medium priority: Ubuntu including 1 source packages (libass), 16 status rows across 16 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, precise, trusty, upstream, xenial, yakkety, zesty): not-affected 13, released 2, ignored 1. https://ubuntu.com/security/CVE-2016-7970

Affected software / configurations for CVE-2016-7970

Vendor Product Version Raw CPE
fedoraproject fedora 23 cpe:2.3:o:fedoraproject:fedora:23:*:*:*:*:*:*:*
fedoraproject fedora 24 cpe:2.3:o:fedoraproject:fedora:24:*:*:*:*:*:*:*
fedoraproject fedora 25 cpe:2.3:o:fedoraproject:fedora:25:*:*:*:*:*:*:*
libass_project libass <= 0.13.3 cpe:2.3:a:libass_project:libass:*:*:*:*:*:*:*:*

References for CVE-2016-7970

URL Tags
http://www.openwall.com/lists/oss-security/2016/10/05/2 Mailing List Patch Third Party Advisory
http://www.securityfocus.com/bid/93358 Third Party Advisory VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=1381960 Issue Tracking Patch
https://github.com/libass/libass/pull/240/commits/08e754612019ed84d1db0d1fc4f5798248decd75 Issue Tracking Patch Third Party Advisory
https://github.com/libass/libass/releases/tag/0.13.4 Patch Release Notes Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KW6DNERYHPI5Y6SQYU3XKTVSCOWMIHUC/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/R7JJ2SGVOX6UQQIRMVC3QACJLKHE2PYN/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VUOUOK3VULMMZTNSCRFCNPDAPDWAVK7X/
https://security.gentoo.org/glsa/201702-25 Patch Third Party Advisory VDB Entry
cvelogic Threat Intelligence