CVE-2016-10197

Exp

The search_make_new function in evdns.c in libevent before 2.1.6-beta allows attackers to cause a denial of service (out-of-bounds read) via an empty hostname.

Published: 2017-03-15 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-10197 is rated High Exploit Risk (80.2/100): CVSS High severity, with high exploitation likelihood (EPSS 5.19%, 91th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +3.21% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2016-10197

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2016-10197

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 1.99% 5.19% +3.21%
2 2026-05-27 2.42% 1.99% -0.43%
3 2026-03-29 — 2.42% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-10197

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/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-2016-10197

OS Trackers for CVE-2016-10197

vendor priority summary link
alpine — CVE-2016-10197: 1 source package rows (libevent); 10 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 0. https://security.alpinelinux.org/vuln/CVE-2016-10197
debian not yet assigned CVE-2016-10197 not yet assigned priority: Debian including 1 source packages (libevent), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2016-10197
gentoo high CVE-2016-10197: 2 GLSA(s) (201705-01, 201802-03), 3 atom(s) (dev-libs/libevent, www-client/firefox, www-client/firefox-bin); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-10197
redhat low — https://access.redhat.com/security/cve/CVE-2016-10197
suse medium — https://www.suse.com/security/cve/CVE-2016-10197/
ubuntu low CVE-2016-10197 low priority: Ubuntu including 3 source packages (firefox, libevent, thunderbird), 17 status rows across 6 suites (precise, trusty, upstream, xenial, yakkety, zesty): released 15, ignored 1, needs-triage 1. https://ubuntu.com/security/CVE-2016-10197

Affected software / configurations for CVE-2016-10197

Vendor Product Version Raw CPE
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
libevent_project libevent <= 2.1.5 cpe:2.3:a:libevent_project:libevent:*:*:*:*:*:*:*:*

References for CVE-2016-10197

URL Tags
http://www.debian.org/security/2017/dsa-3789 Third Party Advisory
http://www.openwall.com/lists/oss-security/2017/01/31/17 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2017/02/02/7 Mailing List Third Party Advisory
http://www.securityfocus.com/bid/96014 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1038320 Broken Link Third Party Advisory VDB Entry
https://access.redhat.com/errata/RHSA-2017:1104 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:1106 Third Party Advisory
https://access.redhat.com/errata/RHSA-2017:1201 Third Party Advisory
https://github.com/libevent/libevent/blob/release-2.1.6-beta/ChangeLog Release Notes Third Party Advisory
https://github.com/libevent/libevent/commit/ec65c42052d95d2c23d1d837136d1cf1d9ecef9e Patch Third Party Advisory
https://github.com/libevent/libevent/issues/332 Exploit Issue Tracking Third Party Advisory
https://security.gentoo.org/glsa/201705-01 Third Party Advisory
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