CVE-2021-31998 | inn: %post calls user owned file allowing local privilege escalation to root

Exp

A Incorrect Default Permissions vulnerability in the packaging of inn of SUSE Linux Enterprise Server 11-SP3; openSUSE Backports SLE-15-SP2, openSUSE Leap 15.2 allows local attackers to escalate their privileges from the news user to root. This issue affects: SUSE Linux Enterprise Server 11-SP3 inn version inn-2.4.2-170.21.3.1 and prior versions. openSUSE Backports SLE-15-SP2 inn versions prior to 2.6.2. openSUSE Leap 15.2 inn versions prior to 2.6.2.

Published: 2021-06-10 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-31998 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). 1 public exploit reference(s) are indexed (Exploit-DB). 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-2021-31998

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

Exploit prediction scoring system (EPSS) score for CVE-2021-31998

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 0.05% 0.03% -0.02%
2 2025-03-29 0.04% 0.05% +0.01%
3 2023-03-07 — 0.04% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-31998

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.8 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N 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: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:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.5 4.2 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H 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: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.
 1.8 5.9 [email protected]
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
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.
 3.9 10.0 [email protected]

Weakness enumeration for CVE-2021-31998

OS Trackers for CVE-2021-31998

vendor priority summary link
debian unimportant CVE-2021-31998 unimportant priority: Debian including 1 source packages (inn2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-31998
suse high CVE-2021-31998 severity important: SUSE including 10 source package names (inn-2.4.2-170.21.3.6.1, inn-2.6.2-bp152.2.8.1, …), 16 product×package rows across 8 product lines (SUSE Linux Enterprise Point of Sale 11 SP3, SUSE Linux Enterprise Server 11 SP1-TERADATA, … (8 product lines)): Fixed 16. https://www.suse.com/security/cve/CVE-2021-31998/
ubuntu medium CVE-2021-31998 medium priority: Ubuntu including 1 source packages (inn2), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 8, needs-triage 6, DNE 1, not-affected 1. https://ubuntu.com/security/CVE-2021-31998

Affected software / configurations for CVE-2021-31998

Vendor Product Version Raw CPE
opensuse inn <= 2.4.2-170.21.3.1 cpe:2.3:a:opensuse:inn:*:*:*:*:*:*:*:*
opensuse inn < 2.6.2 cpe:2.3:a:opensuse:inn:*:*:*:*:*:*:*:*

References for CVE-2021-31998

URL Tags
https://bugzilla.suse.com/show_bug.cgi?id=1182321 Exploit Issue Tracking Vendor Advisory
cvelogic Threat Intelligence