CVE-2024-53991
Published: 19 December 2024
Summary
CVE-2024-53991 is a high-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Discourse Discourse. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked in the top 2.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
Discourse, an open source discussion platform, contains an information disclosure vulnerability that affects only instances configured with FileStore::LocalStore for local disk storage of uploads and backups. The flaw allows an unauthenticated remote attacker who knows the name of a backup file to craft a request that causes nginx to serve the file, exposing its contents. The issue carries a CVSS 3.1 score of 7.5 and is tracked under CWE-200.
An attacker can exploit the weakness over the network without authentication or user interaction to retrieve sensitive backup archives, resulting in high-impact confidentiality loss while integrity and availability remain unaffected. Because the attack requires knowledge of the backup filename, the practical risk depends on whether that name can be guessed or discovered through other means.
The GitHub Security Advisory GHSA-567m-82f6-56rv states that the vulnerability is fixed in the latest stable, beta, and tests-passed releases of Discourse. Administrators unable to upgrade immediately are advised either to download all local backups to another location, disable the enable_backups setting, and delete existing backups, or to change the backup_location setting to s3 so that backups are stored and served directly from S3. The EPSS score stands at 0.5312 with no material increase reported after disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-52229
Vulnerability details
Discourse is an open source platform for community discussion. This vulnerability only impacts Discourse instances configured to use `FileStore::LocalStore` which means uploads and backups are stored locally on disk. If an attacker knows the name of the Discourse backup file,…
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the attacker can trick nginx into sending the Discourse backup file with a well crafted request. This issue is patched in the latest stable, beta and tests-passed versions of Discourse. Users are advised to upgrade. Users unable to upgrade can either 1. Download all local backups on to another storage device, disable the `enable_backups` site setting and delete all backups until the site has been upgraded to pull in the fix. Or 2. Change the `backup_location` site setting to `s3` so that backups are stored and downloaded directly from S3.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability enables remote, unauthenticated access to sensitive local backup files (containing database dumps with user data and credentials) via crafted nginx HTTP requests, facilitating exploitation of public-facing web applications, collection of data from the local system, and access to unsecured credentials in files.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Automated marking applies security attributes to system outputs, making it harder for attackers to exploit unmarked sensitive information leading to unauthorized exposure.
Proper attribute retention and permitted-value enforcement limits unauthorized actors from accessing sensitive information lacking correct labels.
Prevents unauthorized exposure of sensitive information by prohibiting untrusted external systems from processing or storing it.
By enforcing authorization matching prior to sharing, the control reduces the risk of exposing sensitive information to unauthorized actors.
Review and removal of nonpublic information from publicly accessible systems directly prevents exposure of sensitive data to unauthorized actors.
Data mining protection mechanisms detect and block unauthorized bulk extraction of sensitive data, directly mitigating exposure to unauthorized actors.
Literacy training teaches users to recognize and avoid actions that result in unauthorized exposure of sensitive information.
Retaining and monitoring training records confirms personnel have completed privacy and security awareness training on handling sensitive data, reducing the chance of unauthorized exposure due to lack of knowledge.