CVE-2020-8020 | Persistent XSS in markdown parser used by obs-server

A Improper Neutralization of Input During Web Page Generation vulnerability in open-build-service allows remote attackers to store arbitrary JS code to cause XSS. This issue affects: openSUSE open-build-service versions prior to 7cc32c8e2ff7290698e101d9a80a9dc29a5500fb.

Published: 2020-05-13 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-8020 is rated Moderate Risk (43.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.15%). 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-2020-8020

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 2023-05-17 0.15% 0.15% +0.00%
2 2023-03-07 1.05% 0.15% -0.91%
3 2022-04-01 — 1.05% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-8020

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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:L)
Some sensitive info could get out, but not a total data dump.
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.
 3.9 2.5 [email protected]
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
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.
 2.8 2.7 [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-2020-8020

OS Trackers for CVE-2020-8020

vendor priority summary link
debian not yet assigned CVE-2020-8020 not yet assigned priority: Debian including 1 source packages (open-build-service), 2 status rows across 2 suites (bookworm, sid): resolved 2. https://security-tracker.debian.org/tracker/CVE-2020-8020
suse high — https://www.suse.com/security/cve/CVE-2020-8020/
ubuntu medium CVE-2020-8020 medium priority: Ubuntu including 1 source packages (open-build-service), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 7, ignored 6, needs-triage 4. https://ubuntu.com/security/CVE-2020-8020

Affected software / configurations for CVE-2020-8020

Vendor Product Version Raw CPE
opensuse open_build_service < 2020-05-13 cpe:2.3:a:opensuse:open_build_service:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2020-8020

URL Tags
https://bugzilla.suse.com/show_bug.cgi?id=1171439 Issue Tracking Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/02/msg00006.html Mailing List Third Party Advisory
cvelogic Threat Intelligence