HTTP/2 trailer out-of-bounds read

libcurl contains an out bounds read in code handling HTTP/2 trailers. It was reported that reading an HTTP/2 trailer could mess up future trailers since the stored size was one byte less than required. The problem is that the code that creates HTTP/1-like headers from the HTTP/2 trailer data once...

FTP wildcard out of bounds read

libcurl contains a read out of bounds flaw in the FTP wildcard function. libcurl's FTP wildcard matching feature, which is enabled with the CURLOPTWILDCARDMATCH option can use a built-in wildcard function or a user provided one. The built-in wildcard function has a flaw that makes it not detect t...

SSL out of buffer access

libcurl contains an out boundary access flaw in SSL related code. When allocating memory for a connection the internal struct called connectdata, a certain amount of memory is allocated at the end of the struct to be used for SSL related structs. Those structs are used by the particular SSL libra...

FTP PWD response parser out of bounds read

libcurl may read outside of a heap allocated buffer when doing FTP. 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...

use of connection struct after free

libcurl is vulnerable to a use after free flaw. libcurl works with easy handles using the type 'CURL ' that are objects the application creates using curleasyinit. They are the handles that are all each associated with a single transfer at a time. libcurl also has an internal struct that represen...

TFTP Packet Buffer Overflow

libcurl uses the given file part of a TFTP URL in a manner that allows a malicious user to overflow a heap-based memory buffer due to the lack of boundary check. This overflow happens if you pass in a URL with a TFTP protocol prefix "tftp://", using a valid host and a path part that is longer tha...

Non-preserved file permissions

When curl saves cookies, alt-svc and hsts data to local files, it makes the operation atomic by finalizing the operation with a rename from a temporary name to the final target filename. In that rename operation, it might accidentally widen the permissions for the target file, leaving the updated...

CERTINFO never-ending busy-loop

libcurl provides the CURLOPTCERTINFO option to allow applications to request details to be returned about a TLS server's certificate chain. Due to an erroneous function, a malicious server could make libcurl built with NSS get stuck in a never-ending busy-loop when trying to retrieve that...

HSTS bypass via trailing dot

curl's HSTS check could be bypassed to trick it to keep using HTTP. Using its HSTS support, curl can be instructed to use HTTPS directly instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. This mechanism could be bypassed if the hostname in the given URL used ...

Automatic referer leaks credentials

libcurl does not strip off user credentials from the URL when automatically populating the Referer: HTTP request header field in outgoing HTTP requests, and therefore risks leaking sensitive data to the server that is the target of the second HTTP request. libcurl automatically sets the Referer:...

Integer overflows in URL parser

libcurl contains two integer overflows in the curlurlset function that if triggered, can lead to a too small buffer allocation and a subsequent heap buffer overflow. The flaws only exist on 32-bit architectures and require excessive string input lengths...

printf floating point buffer overflow

libcurl's implementation of the printf functions triggers a buffer overflow when doing a large floating point output. The bug occurs when the conversion outputs more than 255 bytes. The flaw happens because the floating point conversion is using system functions without the correct boundary check...

invalid URL parsing with '#'

curl does not parse the authority component of the URL correctly when the host name part ends with a hash character, and could instead be tricked into connecting to a different host. This may have security implications if you for example use a URL parser that follows the RFC to check for allowed...

cookie parser out of boundary memory access

libcurl supports HTTP "cookies" as documented in RFC 6265. Together with each individual cookie there are several different properties, but for this vulnerability we focus on the associated "path" element. It tells information about for which path on a given host the cookie is valid. The internal...

URL Buffer Overflow

libcurl's URL parser function can overflow a heap based buffer in two ways, if given a too long URL. These overflows happen if you 1 - pass in a URL with no protocol like "http://" prefix, using no slash and the string is 256 bytes or longer. This leads to a single zero byte overflow of the heap...