CVE-2018-20239

Application Links before version 5.0.11, from version 5.1.0 before 5.2.10, from version 5.3.0 before 5.3.6, from version 5.4.0 before 5.4.12, and from version 6.0.0 before 6.0.4 allows remote attackers to inject arbitrary HTML or JavaScript via a cross site scripting (XSS) vulnerability in the applinkStartingUrl parameter. The product is used as a plugin in various Atlassian products where the following are affected: Confluence before version 6.15.2, Crucible before version 4.7.0, Crowd before version 3.4.3, Fisheye before version 4.7.0, Jira before version 7.13.3 and 8.x before 8.1.0.

Published: 2019-04-30 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-20239 is rated Moderate Risk (55/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.40%). EPSS rose +2.85% over the last day, indicating growing attacker interest. 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-2018-20239

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 0.55% 3.40% +2.85%
2 2026-02-13 0.56% 0.55% -0.01%
3 2025-12-28 — 0.56% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-20239

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/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: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: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.
 2.3 2.7 [email protected]
3.5 2.0 LOW
AV:N/AC:M/Au:S/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:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 6.8 2.9 [email protected]

Weakness enumeration for CVE-2018-20239

Affected software / configurations for CVE-2018-20239

Vendor Product Version Raw CPE
atlassian application_links < 5.0.11 cpe:2.3:a:atlassian:application_links:*:*:*:*:*:*:*:*
atlassian application_links >= 5.1.0, < 5.2.10 cpe:2.3:a:atlassian:application_links:*:*:*:*:*:*:*:*
atlassian application_links >= 5.3.0, < 5.3.6 cpe:2.3:a:atlassian:application_links:*:*:*:*:*:*:*:*
atlassian application_links >= 5.4.0, < 5.4.12 cpe:2.3:a:atlassian:application_links:*:*:*:*:*:*:*:*
atlassian application_links >= 6.0.0, < 6.0.4 cpe:2.3:a:atlassian:application_links:*:*:*:*:*:*:*:*
atlassian confluence_data_center < 6.15.2 cpe:2.3:a:atlassian:confluence_data_center:*:*:*:*:*:*:*:*
atlassian confluence_server < 6.15.2 cpe:2.3:a:atlassian:confluence_server:*:*:*:*:*:*:*:*
atlassian crowd < 3.4.3 cpe:2.3:a:atlassian:crowd:*:*:*:*:*:*:*:*
atlassian crucible < 4.7.0 cpe:2.3:a:atlassian:crucible:*:*:*:*:*:*:*:*
atlassian fisheye < 4.7.0 cpe:2.3:a:atlassian:fisheye:*:*:*:*:*:*:*:*
atlassian jira_data_center < 7.13.3 cpe:2.3:a:atlassian:jira_data_center:*:*:*:*:*:*:*:*
atlassian jira_data_center >= 8.0.0, < 8.1.0 cpe:2.3:a:atlassian:jira_data_center:*:*:*:*:*:*:*:*
atlassian jira_server < 7.13.3 cpe:2.3:a:atlassian:jira_server:*:*:*:*:*:*:*:*
atlassian jira_server >= 8.0.0, < 8.1.0 cpe:2.3:a:atlassian:jira_server:*:*:*:*:*:*:*:*

References for CVE-2018-20239

URL Tags
https://ecosystem.atlassian.net/browse/APL-1373 Issue Tracking Vendor Advisory
https://jira.atlassian.com/browse/CONFSERVER-58208 Issue Tracking Vendor Advisory
https://jira.atlassian.com/browse/CRUC-8379 Issue Tracking Vendor Advisory
https://jira.atlassian.com/browse/CWD-5362 Issue Tracking Vendor Advisory
https://jira.atlassian.com/browse/FE-7161 Issue Tracking Vendor Advisory
https://jira.atlassian.com/browse/JRASERVER-68855 Issue Tracking Vendor Advisory
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