SB2026091517 - Multiple vulnerabilities in Tornado

Description

This security bulletin contains information about 3 vulnerabilities.

1) Allocation of Resources Without Limits or Throttling (CVE-ID: N/A)

CWE-ID: CWE-770 - Allocation of Resources Without Limits or Throttling

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to allocation of resources without limits in the HTTPServerRequest.__init__ query-string parsing path when processing a GET request with a query string containing thousands of fields. A remote attacker can send a specially crafted GET request with a high number of query-string fields to cause a denial of service.

2) Improper handling of highly compressed data (CVE-ID: N/A)

CWE-ID: CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper handling of highly compressed data in tornado.curl_httpclient.CurlAsyncHTTPClient when processing a gzip-compressed response from an attacker-controlled URL. A remote attacker can serve a decompression bomb to cause a denial of service.

The issue affects applications configured to use the curl HTTP client.

3) Path traversal (CVE-ID: N/A)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to improper path validation in tornado.web.StaticFileHandler when handling requests for paths that resolve through symbolic links. A remote attacker can request a path to a symbolic link within the static root to disclose sensitive information.

Exploitation requires a symbolic link within the static root that points outside that root.

Remediation

Install update from vendor's website.

References

• https://github.com/tornadoweb/tornado/security/advisories/GHSA-3hv7-mjh2-fv65
• https://github.com/tornadoweb/tornado/security/advisories/GHSA-chx6-46f5-w4vp
• https://github.com/tornadoweb/tornado/security/advisories/GHSA-c2m8-h5v5-343r