SASL buffer overflow

libcurl is vulnerable to a buffer overflow vulnerability when communicating with one of the protocols POP3, SMTP or IMAP. When negotiating SASL DIGEST-MD5 authentication, the function Curlsaslcreatedigestmd5message uses the data provided from the server without doing the proper length checks and...

SSL CBC IV vulnerability

curl is vulnerable to a SSL CBC IV vulnerability when built to use OpenSSL for the SSL/TLS layer. This vulnerability has been identified CVE-2011-3389 aka the "BEAST" attack and is addressed by OpenSSL already as they have made a workaround to mitigate the problem. When doing so, they figured out...

URL sanitization vulnerability

curl is vulnerable to a data injection attack for certain protocols through control characters embedded or percent-encoded in URLs. When parsing URLs, libcurl's parser is liberal and only parses as little as possible and lets as much as possible through as long as it can figure out what to do. In...

inappropriate GSSAPI delegation

When doing GSSAPI authentication, libcurl unconditionally performs credential delegation. This hands the server a copy of the client's security credentials, allowing the server to impersonate the client to any other using the same GSSAPI mechanism. This is obviously a sensitive operation, which...

local file overwrite

curl offers a command line option --remote-header-name also usable as -J which uses the filename of the Content-disposition: header when it saves the downloaded data locally. curl attempts to cut off the directory parts from any given filename in the header to only store files in the current...

data callback excessive length

When downloading data, libcurl hands it over to the application using a callback that is registered by the client software. libcurl then calls that function repeatedly with data until the transfer is complete. The callback is documented to receive a maximum data size of 16K CURLMAXWRITESIZE. Usin...

embedded zero in cert name

SSL and TLS Server certificates contain one or more fields with server name or otherwise matching patterns. These strings are stored as content and length within the certificate, and thus there is no particular terminating character. curl's OpenSSL interfacing code did faulty assumptions about...

Arbitrary File Access

When told to follow a "redirect" automatically, libcurl does not question the new target URL but follows it to any new URL that it understands. As libcurl supports FILE:// URLs, a rogue server can thus "trick" a libcurl-using application to read a local file instead of the remote one. This is a...

GnuTLS insufficient cert verification

libcurl when built to use GnuTLS fails to verify that a peer's certificate has not already expired or has not yet become valid. This allows malicious servers to present certificates to libcurl that were not rejected properly. Notably, the CA certificate and common name checks are still in place...

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...

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...

NTLM Buffer Overflow

libcurl's NTLM function can overflow a stack-based buffer if given a too long username or domain name. This would happen if you enable NTLM authentication and either: A - pass in a username and domain name to libcurl that together are longer than 192 bytes B - allow libcurl to follow HTTP...

Authentication Buffer Overflows

Due to bad usage of the base64 decode function to a stack-based buffer without checking the data length, it was possible for a malicious HTTP server to overflow the client during NTLM negotiation and for an FTP server to overflow the client during krb4 negotiation. The announcement of this flaw w...

Proxy Authentication Header Information Leakage

When curl connected to a site via an HTTP proxy with the CONNECT request, the user and password used for the proxy connection was also sent off to the remote server...

FTP Server Response Buffer Overflow

When storing an FTP server's error message on failure, there was no check for input length and thus a malicious FTP server could overflow curl's stack based buffer...