CVE-2021-36158

In the xrdp package (in branches through 3.14) for Alpine Linux, RDP sessions are vulnerable to man-in-the-middle attacks because pre-generated RSA certificates and private keys are used.

Published: 2021-07-05 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-36158 is rated Low Risk (33/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.35%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2021-36158

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 0.15% 0.35% +0.20%
2 2025-04-24 0.17% 0.15% -0.02%
3 2025-03-30 — 0.17% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-36158

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
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:P/I:N/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:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-36158

OS Trackers for CVE-2021-36158

vendor priority summary link
alpine medium CVE-2021-36158: 1 source package rows (xrdp); 8 state rows across 8 repos (3.11-main, 3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 8, open 0. https://security.alpinelinux.org/vuln/CVE-2021-36158
debian unimportant CVE-2021-36158 unimportant priority: Debian including 1 source packages (xrdp), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-36158
ubuntu medium CVE-2021-36158 medium priority: Ubuntu including 1 source packages (xrdp), 12 status rows across 12 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, trusty, upstream, xenial): not-affected 12. https://ubuntu.com/security/CVE-2021-36158

Affected software / configurations for CVE-2021-36158

Vendor Product Version Raw CPE
alpinelinux aports <= 3.14 cpe:2.3:a:alpinelinux:aports:*:*:*:*:*:alpine:*:*

References for CVE-2021-36158

cvelogic Threat Intelligence