CVE-2017-9803

Apache Solr's Kerberos plugin can be configured to use delegation tokens, which allows an application to reuse the authentication of an end-user or another application. There are two issues with this functionality (when using SecurityAwareZkACLProvider type of ACL provider e.g. SaslZkACLProvider). Firstly, access to the security configuration can be leaked to users other than the solr super user. Secondly, malicious users can exploit this leaked configuration for privilege escalation to further expose/modify private data and/or disrupt operations in the Solr cluster. The vulnerability is fixed from Apache Solr 6.6.1 onwards.

Published: 2017-09-18 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-9803 is rated Moderate Risk (59/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.20%). 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-2017-9803

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 1.23% 2.20% +0.97%
2 2026-04-29 1.55% 1.23% -0.31%
3 2026-03-13 — 1.55% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-9803

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H 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:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.6 5.9 [email protected]
6.0 2.0 MEDIUM
AV:N/AC:M/Au:S/C:P/I:P/A:P 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:P)
Partial availability impact.
 6.8 6.4 [email protected]

Weakness enumeration for CVE-2017-9803

GitHub Security Advisory for CVE-2017-9803

GHSA-f553-j2gv-g5r9 · Severity: high · Ecosystem: maven — Apache Solr Kerberos delegation token functionality flaws

OS Trackers for CVE-2017-9803

vendor priority summary link
debian unimportant CVE-2017-9803 unimportant priority: Debian including 1 source packages (lucene-solr), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2017-9803
redhat high — https://access.redhat.com/security/cve/CVE-2017-9803
ubuntu medium CVE-2017-9803 medium priority: Ubuntu including 1 source packages (lucene-solr), 4 status rows across 4 suites (trusty, upstream, xenial, zesty): not-affected 3, needs-triage 1. https://ubuntu.com/security/CVE-2017-9803

Affected software / configurations for CVE-2017-9803

Vendor Product Version Raw CPE
apache solr 6.2.0 cpe:2.3:a:apache:solr:6.2.0:*:*:*:*:*:*:*
apache solr 6.2.1 cpe:2.3:a:apache:solr:6.2.1:*:*:*:*:*:*:*
apache solr 6.3.0 cpe:2.3:a:apache:solr:6.3.0:*:*:*:*:*:*:*
apache solr 6.4.0 cpe:2.3:a:apache:solr:6.4.0:*:*:*:*:*:*:*
apache solr 6.4.1 cpe:2.3:a:apache:solr:6.4.1:*:*:*:*:*:*:*
apache solr 6.4.2 cpe:2.3:a:apache:solr:6.4.2:*:*:*:*:*:*:*
apache solr 6.5.0 cpe:2.3:a:apache:solr:6.5.0:*:*:*:*:*:*:*
apache solr 6.5.1 cpe:2.3:a:apache:solr:6.5.1:*:*:*:*:*:*:*
apache solr 6.6.0 cpe:2.3:a:apache:solr:6.6.0:*:*:*:*:*:*:*

References for CVE-2017-9803

cvelogic Threat Intelligence