CVE-2017-16858

The 'crowd-application' plugin module (notably used by the Google Apps plugin) in Atlassian Crowd from version 1.5.0 before version 3.1.2 allowed an attacker to impersonate a Crowd user in REST requests by being able to authenticate to a directory bound to an application using the feature. Given the following situation: the Crowd application is bound to directory 1 and has a user called admin and the Google Apps application is bound to directory 2, which also has a user called admin, it was possible to authenticate REST requests using the credentials of the user coming from directory 2 and impersonate the user from directory 1.

Published: 2018-01-31 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2017-16858 is rated Moderate Risk (42.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.58%). Mandatory action: 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-2017-16858

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 0.14% 0.58% +0.43%
2 2025-08-17 0.15% 0.14% -0.01%
3 2025-07-30 0.15%

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-16858

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.8 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/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: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:N)
Service keeps running; no real outage angle.
1.6 5.2 [email protected]
4.9 2.0 MEDIUM
AV:N/AC:M/Au:S/C:P/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:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
6.8 4.9 [email protected]

Weakness enumeration for CVE-2017-16858

Affected software / configurations for CVE-2017-16858

Vendor Product Version Raw CPE
atlassian crowd >= 1.5.0, < 3.1.2 cpe:2.3:a:atlassian:crowd:*:*:*:*:*:*:*:*

References for CVE-2017-16858

URL Tags
https://jira.atlassian.com/browse/CWD-5009 Issue Tracking Vendor Advisory
cvelogic Threat Intelligence