Haxx Curl

An improper certificate validation vulnerability exists in curl <v8.1.0 in the way it supports matching of wildcard patterns when listed as "Subject Alternative Name" in TLS server certificates. curl can be built to use its own name matching function for TLS rather than one provided by a TLS library. This private wildcard matching function would match IDN (International Domain Name) hosts incorrectly and could as a result accept patterns that otherwise should mismatch. IDN hostnames are converted to puny code before used for certificate checks. Puny coded names always start with `xn--` and should not be allowed to pattern match, but the wildcard check in curl could still check for `x*`, which would match even though the IDN name most likely contained nothing even resembling an `x`.

proxy credentials leak over redirect-to proxy

connection reuse ignores TLS requirement

No QUIC certificate pinning with GnuTLS

cURL and libcurl 7.1 before 7.36.0, when using the OpenSSL, axtls, qsossl or gskit libraries for TLS, recognize a wildcard IP address in the subject's Common Name (CN) field of an X.509 certificate, which might allow man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority.

An insufficiently protected credentials vulnerability exists in curl 4.9 to and include curl 7.82.0 are affected that could allow an attacker to extract credentials when follows HTTP(S) redirects is used with authentication could leak credentials to other services that exist on different protocols or port numbers.

The (1) mbed_connect_step1 function in lib/vtls/mbedtls.c and (2) polarssl_connect_step1 function in lib/vtls/polarssl.c in cURL and libcurl before 7.49.0, when using SSLv3 or making a TLS connection to a URL that uses a numerical IP address, allow remote attackers to spoof servers via an arbitrary valid certificate.

curl supports the `-t` command line option, known as `CURLOPT_TELNETOPTIONS`in libcurl. This rarely used option is used to send variable=content pairs toTELNET servers.Due to flaw in the option parser for sending `NEW_ENV` variables, libcurlcould be made to pass on uninitialized data from a stack based buffer to theserver. Therefore potentially revealing sensitive internal information to theserver using a clear-text network protocol.This could happen because curl did not call and use sscanf() correctly whenparsing the string provided by the application.

In curl before 7.54.1 on Windows and DOS, libcurl's default protocol function, which is the logic that allows an application to set which protocol libcurl should attempt to use when given a URL without a scheme part, had a flaw that could lead to it overwriting a heap based memory buffer with seven bytes. If the default protocol is specified to be FILE or a file: URL lacks two slashes, the given "URL" starts with a drive letter, and libcurl is built for Windows or DOS, then libcurl would copy the path 7 bytes off, so that the end of the given path would write beyond the malloc buffer (7 bytes being the length in bytes of the ascii string "file://").

curl 7.61.0 through 7.76.1 suffers from exposure of data element to wrong session due to a mistake in the code for CURLOPT_SSL_CIPHER_LIST when libcurl is built to use the Schannel TLS library. The selected cipher set was stored in a single "static" variable in the library, which has the surprising side-effect that if an application sets up multiple concurrent transfers, the last one that sets the ciphers will accidentally control the set used by all transfers. In a worst-case scenario, this weakens transport security significantly.

libcurl wrongly allows cookies to be set for Top Level Domains (TLDs) if thehost name is provided with a trailing dot.curl can be told to receive and send cookies. curl's "cookie engine" can bebuilt with or without [Public Suffix List](https://publicsuffix.org/)awareness. If PSL support not provided, a more rudimentary check exists to atleast prevent cookies from being set on TLDs. This check was broken if thehost name in the URL uses a trailing dot.This can allow arbitrary sites to set cookies that then would get sent to adifferent and unrelated site or domain.

An information disclosure vulnerability exists in curl <v8.1.0 when doing HTTP(S) transfers, libcurl might erroneously use the read callback (`CURLOPT_READFUNCTION`) to ask for data to send, even when the `CURLOPT_POSTFIELDS` option has been set, if the same handle previously wasused to issue a `PUT` request which used that callback. This flaw may surprise the application and cause it to misbehave and either send off the wrong data or use memory after free or similar in the second transfer. The problem exists in the logic for a reused handle when it is (expected to be) changed from a PUT to a POST.

When curl is instructed to get content using the metalink feature, and a user name and password are used to download the metalink XML file, those same credentials are then subsequently passed on to each of the servers from which curl will download or try to download the contents from. Often contrary to the user's expectations and intentions and without telling the user it happened.

cURL before 7.47.0 on Windows allows attackers to write to arbitrary files in the current working directory on a different drive via a colon in a remote file name.

When saving HSTS data to an excessively long file name, curl could end up removing all contents, making subsequent requests using that file unaware of the HSTS status they should otherwise use.

OCSP verification bypass with TLS session reuse

OpenSSL partial chain store policy bypass

bearer token leak on cross-protocol redirect

cross-proxy Digest auth state leak

libssh global known_hosts override

netrc credential leak with reused proxy connection

token leak with redirect and netrc

predictable WebSocket mask

OCSP stapling bypass with Apple SecTrust

cURL and libcurl 7.10.6 through 7.41.0 do not properly re-use authenticated Negotiate connections, which allows remote attackers to connect as other users via a request.

cURL and libcurl 7.10.6 through 7.41.0 does not properly re-use NTLM connections, which allows remote attackers to connect as other users via an unauthenticated request, a similar issue to CVE-2014-0015.

cURL and libcurl 7.40.0 through 7.42.1 send the HTTP Basic authentication credentials for a previous connection when reusing a reset (curl_easy_reset) connection handle to send a request to the same host name, which allows remote attackers to obtain sensitive information via unspecified vectors.

The default configuration for cURL and libcurl before 7.42.1 sends custom HTTP headers to both the proxy and destination server, which might allow remote proxy servers to obtain sensitive information by reading the header contents.

cURL and libcurl before 7.38.0 does not properly handle IP addresses in cookie domain names, which allows remote attackers to set cookies for or send arbitrary cookies to certain sites, as demonstrated by a site at 192.168.0.1 setting cookies for a site at 127.168.0.1.

The tailMatch function in cookie.c in cURL and libcurl before 7.30.0 does not properly match the path domain when sending cookies, which allows remote attackers to steal cookies via a matching suffix in the domain of a URL.

cURL and libcurl before 7.38.0 allow remote attackers to bypass the Same Origin Policy and set cookies for arbitrary sites by setting a cookie for a top-level domain.

No QUIC certificate pinning with wolfSSL

wcurl path traversal with percent-encoded slashes

The SSL protocol, as used in certain configurations in Microsoft Windows and Microsoft Internet Explorer, Mozilla Firefox, Google Chrome, Opera, and other products, encrypts data by using CBC mode with chained initialization vectors, which allows man-in-the-middle attackers to obtain plaintext HTTP headers via a blockwise chosen-boundary attack (BCBA) on an HTTPS session, in conjunction with JavaScript code that uses (1) the HTML5 WebSocket API, (2) the Java URLConnection API, or (3) the Silverlight WebClient API, aka a "BEAST" attack.

A malicious server can serve excessive amounts of `Set-Cookie:` headers in a HTTP response to curl and curl < 7.84.0 stores all of them. A sufficiently large amount of (big) cookies make subsequent HTTP requests to this, or other servers to which the cookies match, create requests that become larger than the threshold that curl uses internally to avoid sending crazy large requests (1048576 bytes) and instead returns an error.This denial state might remain for as long as the same cookies are kept, match and haven't expired. Due to cookie matching rules, a server on `foo.example.com` can set cookies that also would match for `bar.example.com`, making it it possible for a "sister server" to effectively cause a denial of service for a sibling site on the same second level domain using this method.

An integer overflow in curl's URL API results in a buffer overflow in libcurl 7.62.0 to and including 7.64.1.

A malicious server can use the FTP PASV response to trick curl 7.73.0 and earlier into connecting back to a given IP address and port, and this way potentially make curl extract information about services that are otherwise private and not disclosed, for example doing port scanning and service banner extractions.

cURL and libcurl 7.18.0 through 7.32.0, when built with OpenSSL, disables the certificate CN and SAN name field verification (CURLOPT_SSL_VERIFYHOST) when the digital signature verification (CURLOPT_SSL_VERIFYPEER) is disabled, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.

Using its HSTS support, curl can be instructed to use HTTPS directly insteadof using an insecure clear-text HTTP step even when HTTP is provided in theURL. This mechanism could be bypassed if the host name in the given URL used atrailing dot while not using one when it built the HSTS cache. Or the otherway around - by having the trailing dot in the HSTS cache and *not* using thetrailing dot in the URL.

missing SFTP host verification with wolfSSH