BIT-php-2025-14177

In PHP versions:8.1.* before 8.1.34, 8.2.* before 8.2.30, 8.3.* before 8.3.29, 8.4.* before 8.4.16, 8.5.* before 8.5.1, the getimagesize() function may leak uninitialized heap memory into the APPn segments (e.g., APP1) when reading images in multi-chunk mode (such as via php://filter). This occurs due to a bug in phpreadstreamallchunks() that overwrites the buffer without advancing the pointer, leaving tail bytes uninitialized. This may lead to information disclosure of sensitive heap data and affect the confidentiality of the target server.