SB2026052533 - Multiple vulnerabilities in starlette

Description

This security bulletin contains information about 2 vulnerabilities.

1) Unsafe reflection (CVE-ID: N/A)

CWE-ID: CWE-470 - Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to invoke unintended endpoint methods.

The vulnerability exists due to use of externally-controlled input to select code in HTTPEndpoint request dispatch when processing a request with a non-standard HTTP method. A remote attacker can send a specially crafted request to invoke unintended endpoint methods.

Exploitation requires an HTTPEndpoint subclass to be registered through Route(...) without an explicit methods= argument, and the subclass must expose additional methods whose names match a non-standard HTTP method token shape, accept a single request argument, and return a response.

2) Server-Side Request Forgery (SSRF) (CVE-ID: N/A)

CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to server-side request forgery (SSRF) in StaticFiles.lookup_path() when processing a UNC path on Windows. A remote attacker can send a specially crafted request containing a UNC path to disclose sensitive information.

Only Windows systems using the default configuration with follow_symlink set to false are affected. The issue can leak the service account's NTLMv2 credentials to an attacker-controlled SMB host.

Remediation

Install update from vendor's website.

References

• https://github.com/Kludex/starlette/security/advisories/GHSA-x746-7m8f-x49c
• https://github.com/Kludex/starlette/security/advisories/GHSA-wqp7-x3pw-xc5r