CVE-2017-10908

H2O version 2.2.3 and earlier allows remote attackers to cause a denial of service in the server via specially crafted HTTP/2 header.

Published: 2017-12-22 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2017-10908 is rated Moderate Risk (56.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.34%). 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-2017-10908

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 2025-03-30 1.85% 1.34% -0.51%
2 2025-03-29 1.34% 1.85% +0.51%
3 2025-03-17 1.34%

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-10908

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-2017-10908

OS Trackers for CVE-2017-10908

vendor priority summary link
debian medium CVE-2017-10908 medium priority: Debian including 1 source packages (h2o), 2 status rows across 2 suites (bookworm, bullseye): resolved 2. https://security-tracker.debian.org/tracker/CVE-2017-10908
ubuntu medium CVE-2017-10908 medium priority: Ubuntu including 1 source packages (h2o), 7 status rows across 7 suites (artful, bionic, cosmic, trusty, upstream, xenial, zesty): DNE 4, not-affected 2, released 1. https://ubuntu.com/security/CVE-2017-10908

Affected software / configurations for CVE-2017-10908

Vendor Product Version Raw CPE
dena h2o <= 2.2.3 cpe:2.3:a:dena:h2o:*:*:*:*:*:*:*:*

References for CVE-2017-10908

URL Tags
https://github.com/h2o/h2o/issues/1544 Third Party Advisory
https://jvn.jp/en/jp/JVN84182676/index.html Third Party Advisory VDB Entry
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