CVE-2023-50386
Apache Solr 6.0.0 – 8.11.3
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-50386 is a high-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Apache Solr. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked in the top 0.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
Apache Solr versions 6.0.0 through 8.11.2 and 9.0.0 before 9.4.1 contain an improper control of dynamically-managed code resources vulnerability, also described as unrestricted upload of files with dangerous types and inclusion of functionality from an untrusted control sphere. In these releases the ConfigSets API accepts Java jar and class files, which are persisted to disk during collection backups that use the default LocalFileSystemRepository; when the backup target lies on a ClassPath or ClassLoader directory, the uploaded artifacts become loadable by any ConfigSet.
An authenticated user who can invoke both the ConfigSets API and the Backup API can therefore place executable code where it will be available to trusted or untrusted configurations alike. When Solr is operated with authorization enabled, the impact is narrowed to an extension of backup privileges that permits addition of arbitrary libraries.
Official guidance from the Apache Solr security page and the coordinated oss-security disclosure recommends immediate upgrade to 8.11.3 or 9.4.1. These releases block upload of files that a Java ClassLoader can execute and restrict the Backup API from writing into ClassLoader directories. The EPSS score has remained near its observed peak of 0.8882 with a current value of 0.8684.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-0481
Vulnerability Data
Improper Control of Dynamically-Managed Code Resources, Unrestricted Upload of File with Dangerous Type, Inclusion of Functionality from Untrusted Control Sphere vulnerability in Apache Solr.This issue affects Apache Solr: from 6.0.0 through 8.11.2, from 9.0.0 before 9.4.1. In the affected versions,…
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Solr ConfigSets accepted Java jar and class files to be uploaded through the ConfigSets API. When backing up Solr Collections, these configSet files would be saved to disk when using the LocalFileSystemRepository (the default for backups). If the backup was saved to a directory that Solr uses in its ClassPath/ClassLoaders, then the jar and class files would be available to use with any ConfigSet, trusted or untrusted. When Solr is run in a secure way (Authorization enabled), as is strongly suggested, this vulnerability is limited to extending the Backup permissions with the ability to add libraries. Users are recommended to upgrade to version 8.11.3 or 9.4.1, which fix the issue. In these versions, the following protections have been added: * Users are no longer able to upload files to a configSet that could be executed via a Java ClassLoader. * The Backup API restricts saving backups to directories that are used in the ClassLoader.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.1.1
Mitigating Controls (NIST 800-53 r5) AI
Access enforcement directly stops unauthorized reads/writes to dynamic code resources by applying authorization checks at access time.
Least privilege reduces the set of subjects that can reach or modify dynamic code resources, limiting the weakness's reach.
Malicious-code protection at entry points blocks dangerous file types from being accepted and executed.
Least functionality restricts the file types and automatic processing capabilities the system will accept.
Mobile-code controls define, authorize, and block unacceptable uploaded code before automatic processing occurs.
Isolating security functions from non-security code prevents unintended manipulation of dynamically managed executable resources.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Hardened configuration baselines can enforce allowed file types and processing rules.
Restricting execution of unauthorized software directly blocks dangerous uploaded files from running.
Secure development practices include input validation and file-type restrictions that prevent this weakness.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.
- No fine-grained STIG row for CWE-913, a class-level weakness, and none of its children carries one either.