Bug #7960: curl: FTP PWD response parser out of bounds read (CVE-2017-1000254)
[3.7] curl: FTP PWD response parser out of bounds read (CVE-2017-1000254)
When libcurl connects to an FTP server and successfully logs in (anonymous or not), it asks the server for the
current directory with the PWD command. The server then responds with a 257 response containing the path,
inside double quotes. The returned path name is then kept by libcurl for subsequent uses.
Due to a flaw in the string parser for this directory name, a directory name passed like this but without a closing
double quote would lead to libcurl not adding a trailing NUL byte to the buffer holding the name. When libcurl would
then later access the string, it could read beyond the allocated heap buffer and crash or wrongly access data
beyond the buffer, thinking it was part of the path.
libcurl 7.7 to and including 7.55.1
Not affected versions:¶
libcurl < 7.7 and >= 7.56.0