CVE-2018-1121

Exp

procps-ng, procps is vulnerable to a process hiding through race condition. Since the kernel's proc_pid_readdir() returns PID entries in ascending numeric order, a process occupying a high PID can use inotify events to determine when the process list is being scanned, and fork/exec to obtain a lower PID, thus avoiding enumeration. An unprivileged attacker can hide a process from procps-ng's utilities by exploiting a race condition in reading /proc/PID entries. This vulnerability affects procps and procps-ng up to version 3.3.15, newer versions might be affected also.

Published: 2018-06-13 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-1121 is rated High Exploit Risk (64.2/100): CVSS Low severity, with medium exploitation likelihood (EPSS 4.19%). 4 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.26% 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-2018-1121

EDB-ID Source Kind Published Link
44806 exploit_db edb 2018-05-30 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2018-1121

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 1.93% 4.19% +2.26%
2 2026-06-06 1.99% 1.93% -0.06%
3 2026-04-11 — 1.99% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-1121

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.9 3.0 LOW
CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L 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:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 1.3 2.5 [email protected]
5.9 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/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: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: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.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:P/A:N 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:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2018-1121

OS Trackers for CVE-2018-1121

vendor priority summary link
debian unimportant CVE-2018-1121 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2018-1121
redhat low — https://access.redhat.com/security/cve/CVE-2018-1121
ubuntu low CVE-2018-1121 low priority: Ubuntu including 177 source packages (linux, linux-allwinner, …), 2430 status rows across 20 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1919, ignored 277, needs-triage 129, deferred 105. https://ubuntu.com/security/CVE-2018-1121

Affected software / configurations for CVE-2018-1121

Vendor Product Version Raw CPE
procps_project procps <= 3.3.15 cpe:2.3:a:procps_project:procps:*:*:*:*:*:*:*:*

References for CVE-2018-1121

URL Tags
http://seclists.org/oss-sec/2018/q2/122 Exploit Mailing List Third Party Advisory
http://www.securityfocus.com/bid/104214 Third Party Advisory VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-1121 Issue Tracking Third Party Advisory
https://www.exploit-db.com/exploits/44806/ Exploit Third Party Advisory VDB Entry
https://www.qualys.com/2018/05/17/procps-ng-audit-report-advisory.txt Exploit Third Party Advisory
cvelogic Threat Intelligence