The author stumbled upon a 24-year-old buffer overflow in glibc, with rare exploitable traits, useful in exploiting the PHP engine. PHP filters, like php://filter, offer stream transformations, allowing customized access to files. They detail converting files to different charsets using filters and discuss PHP weaknesses and programmatically adding prefixes or suffixes. A bug in glibc can lead to out-of-bound writes during charset conversions. The article mentions the impact and exploitation of several vulnerabilities like SQL injection, RCE, and XXE, emphasizing PHP targeting as well as technological improvements and timelines. Ultimately, they express the endless possibilities for exploitation present within PHP chains.
https://www.ambionics.io/blog/iconv-cve-2024-2961-p1