CVE-2016-5823

The icalproperty_new_clone function in libical 0.47 and 1.0 allows remote attackers to cause a denial of service (use-after-free) via a crafted ics file.

Published: 2017-01-27 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-5823 is rated Moderate Risk (43/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.00%). 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-2016-5823

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 0.40% 1.00% +0.60%
2 2025-06-19 0.24% 0.40% +0.16%
3 2025-03-30 — 0.24% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-5823

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.0 MEDIUM
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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.
 1.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/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:M)
Exploitation needs some favorable conditions, but not exceptional ones.
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.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2016-5823

OS Trackers for CVE-2016-5823

vendor priority summary link
gentoo normal CVE-2016-5823: 1 GLSA(s) (201904-02), 1 atom(s) (dev-libs/libical); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-5823
redhat low — https://access.redhat.com/security/cve/CVE-2016-5823
suse medium CVE-2016-5823 severity moderate: SUSE including 11 source package names (libical, libical-devel, …), 49 product×package rows across 20 product lines (SUSE Linux Enterprise Desktop 12, SUSE Linux Enterprise Desktop 12 SP1, … (20 product lines)): Known Not Affected 39, Fixed 10. https://www.suse.com/security/cve/CVE-2016-5823/
ubuntu low CVE-2016-5823 low priority: Ubuntu including 1 source packages (libical), 24 status rows across 24 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, precise, questing, trusty, upstream, wily, xenial, yakkety, zesty): DNE 14, ignored 7, needed 2, needs-triage 1. https://ubuntu.com/security/CVE-2016-5823

Affected software / configurations for CVE-2016-5823

Vendor Product Version Raw CPE
libical_project libical 0.47 cpe:2.3:a:libical_project:libical:0.47:*:*:*:*:*:*:*
libical_project libical 1.0 cpe:2.3:a:libical_project:libical:1.0:*:*:*:*:*:*:*

References for CVE-2016-5823

cvelogic Threat Intelligence