Threats Tagged 'cve-2026-84270'

CVE-2026-84267 is a vulnerability in the SFTP backend of GNOME gvfs where a malicious SFTP server can cause the client to leak uninitialized heap memory. This occurs because the read_string() function allocates a buffer without verifying it is fully filled, leading to uninitialized bytes being used as a file handle and echoed back to the server. The leaked memory includes the heap base and the load address of the libgio library, allowing deterministic defeat of ASLR. The vulnerability requires user interaction to connect to a malicious SFTP share and results in limited information disclosure without exposing user data. It has been rated with moderate severity and affects gvfs versions from 1.10.0 up to but not including 1.60.2.

A flaw was found in the MTP backend in gvfs. When reading a file from a mounted MTP device, do_read() in gvfsbackendmtp.c trusts the data length returned by the device without limiting it to the original size requested by the client. If a malicious MTP device responds with more bytes than requested, this unrestricted length is passed directly to memcpy(). This causes the operation to read memory outside the intended boundaries. This allows an attacker who plugs in a malicious MTP device to cause a segmentation fault when a file is read and crash the gvfsd-mtp process, resulting in a denial of service.