CVE-2018-16949

An issue was discovered in OpenAFS before 1.6.23 and 1.8.x before 1.8.2. Several data types used as RPC input variables were implemented as unbounded array types, limited only by the inherent 32-bit length field to 4 GB. An unauthenticated attacker could send, or claim to send, large input values and consume server resources waiting for those inputs, denying service to other valid connections.

Published: 2018-09-12 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-16949 is rated Moderate Risk (58.5/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.08%). 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-2018-16949

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 4.61% 3.08% -1.53%
2 2025-12-10 5.64% 4.61% -1.03%
3 2025-09-30 — 5.64% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-16949

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-2018-16949

OS Trackers for CVE-2018-16949

vendor priority summary link
debian not yet assigned CVE-2018-16949 not yet assigned priority: Debian including 1 source packages (openafs), 4 status rows across 4 suites (bookworm, bullseye, sid, trixie): resolved 4. https://security-tracker.debian.org/tracker/CVE-2018-16949
ubuntu medium CVE-2018-16949 medium priority: Ubuntu including 1 source packages (openafs), 19 status rows across 19 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 14, needed 2, DNE 1, ignored 1, released 1. https://ubuntu.com/security/CVE-2018-16949

Affected software / configurations for CVE-2018-16949

Vendor Product Version Raw CPE
openafs openafs < 1.6.23 cpe:2.3:a:openafs:openafs:*:*:*:*:*:*:*:*
openafs openafs >= 1.8.0, < 1.8.2 cpe:2.3:a:openafs:openafs:*:*:*:*:*:*:*:*
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:*:*:*:*:*:*:*

References for CVE-2018-16949

cvelogic Threat Intelligence