CVE-2015-8313

GnuTLS incorrectly validates the first byte of padding in CBC modes

Published: 2019-12-20 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2015-8313 is rated Moderate Risk (50.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.69%). 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-2015-8313

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 1.06% 1.69% +0.62%
2 2025-04-24 1.32% 1.06% -0.26%
3 2025-03-30 1.32%

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-8313

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]
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-2015-8313

OS Trackers for CVE-2015-8313

vendor priority summary link
debian unimportant CVE-2015-8313 unimportant 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-2015-8313
redhat low https://access.redhat.com/security/cve/CVE-2015-8313
ubuntu medium CVE-2015-8313 medium priority: Ubuntu including 2 source packages (gnutls26, gnutls28), 10 status rows across 5 suites (precise, trusty, upstream, vivid, wily): not-affected 4, DNE 3, released 3. https://ubuntu.com/security/CVE-2015-8313

Affected software / configurations for CVE-2015-8313

Vendor Product Version Raw CPE
gnu gnutls >= 2.0.0, <= 2.12.24 cpe:2.3:a:gnu:gnutls:*:*:*:*:*:*:*:*
debian debian_linux 7.0 cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2015-8313

cvelogic Threat Intelligence