Security researcher Masato Kinugawa found that during the decoding of ISO-2022-KR and ISO-2022-CN character sets, characters near 1024 bytes are treated incorrectly, either doubling or deleting bytes. On certain pages it might be possible for an attacker to pad the output of the page such that these errors fall in the right place to affect the structure of the page, allowing for cross-site script (XSS) injection.
Vulmon