curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a
server, even if the new request uses different credentials for the HTTP proxy.
The proper behavior is to create or use a separate connection.
When doing SSH-based transfers using either SCP or SFTP, and asked to do
public key authentication, curl would wrongly still ask and authenticate using
a locally running SSH agent.
When doing SSH-based transfers using either SCP or SFTP, and setting the
known_hosts file, libcurl could still mistakenly accept connecting to hosts
*not present* in the specified file if they were added as recognized in the
libssh *global* known_hosts file.
Media · CVSS 5.3EPSS 0,68%Sin corrección publicada
bearer token leak on cross-protocol redirect
When an OAuth2 bearer token is used for an HTTP(S) transfer, and that transfer
performs a cross-protocol redirect to a second URL that uses an IMAP, LDAP,
POP3 or SMTP scheme, curl might wrongly pass on the bearer token to the new
target host.
When doing multi-threaded LDAPS transfers (LDAP over TLS) with libcurl,
changing TLS options in one thread would inadvertently change them globally
and therefore possibly also affect other concurrently setup transfers.
Disabling certificate verification for a specific transfer could
unintentionally disable the feature for other threads as well.
When asked to both use a `.netrc` file for credentials and to follow HTTP
redirects, curl could leak the password used for the first host to the
followed-to host under certain circumstances.
This flaw only manifests itself if the netrc file has an entry that matches
the redirect target hostname but the entry either omits just the password or
omits both login and password.
When curl is told to use the Certificate Status Request TLS extension, often referred to as OCSP stapling, to verify that the server certificate is valid, it might fail to detect some OCSP problems and instead wrongly consider the response as fine. If the returned status reports another error than 'revoked' (like for example 'unauthorized') it is not treated as a bad certficate.
libcurl's ASN1 parser code has the `GTime2str()` function, used for parsing an
ASN.1 Generalized Time field. If given an syntactically incorrect field, the
parser might end up using -1 for the length of the *time fraction*, leading to
a `strlen()` getting performed on a pointer to a heap buffer area that is not
(purposely) null terminated.
This flaw most likely leads to a crash, but can also lead to heap contents
getting returned to the application when
[CURLINFO_CERTINFO](https://curl.se/libcurl/c/CURLINFO_CERTINFO.html) is used.
When an application tells libcurl it wants to allow HTTP/2 server push, and the amount of received headers for the push surpasses the maximum allowed limit (1000), libcurl aborts the server push. When aborting, libcurl inadvertently does not free all the previously allocated headers and instead leaks the memory. Further, this error condition fails silently and is therefore not easily detected by an application.
This flaw allows a malicious HTTP server to set "super cookies" in curl that
are then passed back to more origins than what is otherwise allowed or
possible. This allows a site to set cookies that then would get sent to
different and unrelated sites and domains.
It could do this by exploiting a mixed case flaw in curl's function that
verifies a given cookie domain against the Public Suffix List (PSL). For
example a cookie could be set with `domain=co.UK` when the URL used a lower
case hostname `curl.co.uk`, even though `co.uk` is listed as a PSL domain.
This flaw allows an attacker to insert cookies at will into a running program
using libcurl, if the specific series of conditions are met.
libcurl performs transfers. In its API, an application creates "easy handles"
that are the individual handles for single transfers.
libcurl provides a function call that duplicates en easy handle called
[curl_easy_duphandle](https://curl.se/libcurl/c/curl_easy_duphandle.html).
If a transfer has cookies enabled when the handle is duplicated, the
cookie-enable state is also cloned - but without cloning the actual
cookies. If the source handle did not read any cookies from a specific file on
disk, the clon
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.
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 wildc