CVE-2018-17953 | pam_access does not handle netmask matches correctly

A incorrect variable in a SUSE specific patch for pam_access rule matching in PAM 1.3.0 in openSUSE Leap 15.0 and SUSE Linux Enterprise 15 could lead to pam_access rules not being applied (fail open).

Published: 2018-11-27 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-17953 is rated Moderate Risk (54.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.34%). 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-2018-17953

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 0.43% 1.34% +0.91%
2 2025-04-10 0.49% 0.43% -0.06%
3 2025-03-30 — 0.49% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-17953

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:H/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: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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
8.1 3.0 HIGH
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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: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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 5.9 [email protected]
9.3 2.0 HIGH
AV:N/AC:M/Au:N/C:C/I:C/A:C 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:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 8.6 10.0 [email protected]

Weakness enumeration for CVE-2018-17953

OS Trackers for CVE-2018-17953

vendor priority summary link
debian unimportant CVE-2018-17953 unimportant priority: Debian including 1 source packages (pam), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-17953
redhat medium — https://access.redhat.com/security/cve/CVE-2018-17953
suse medium CVE-2018-17953 severity moderate: SUSE including 515 source package names (0.0.17-1.1:pam-1.3.0-6.6.1, 0.1.0:pam-1.3.0-6.6.1, …), 1015 product×package rows across 599 product lines (Container bci/bci-init, Container bci/bci-sle15-kernel-module-devel, … (599 product lines)): Fixed 776, Known Affected 157, Known Not Affected 82. https://www.suse.com/security/cve/CVE-2018-17953/
ubuntu low CVE-2018-17953 low priority: Ubuntu including 1 source packages (pam), 5 status rows across 5 suites (bionic, cosmic, trusty, upstream, xenial): not-affected 5. https://ubuntu.com/security/CVE-2018-17953

Affected software / configurations for CVE-2018-17953

Vendor Product Version Raw CPE
kernel linux-pam 1.3.0 cpe:2.3:a:kernel:linux-pam:1.3.0:*:*:*:*:*:*:*

References for CVE-2018-17953

cvelogic Threat Intelligence