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 was used 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 subsequent `POST` request. The problem exists in the logic for a reused handle when it is changed from a PUT to a POST.
CVSS Score
9.8
EPSS Score
0.043
Published
2022-12-05
curl before 7.86.0 has a double free. If curl is told to use an HTTP proxy for a transfer with a non-HTTP(S) URL, it sets up the connection to the remote server by issuing a CONNECT request to the proxy, and then tunnels the rest of the protocol through. An HTTP proxy might refuse this request (HTTP proxies often only allow outgoing connections to specific port numbers, like 443 for HTTPS) and instead return a non-200 status code to the client. Due to flaws in the error/cleanup handling, this could trigger a double free in curl if one of the following schemes were used in the URL for the transfer: dict, gopher, gophers, ldap, ldaps, rtmp, rtmps, or telnet. The earliest affected version is 7.77.0.
CVSS Score
8.1
EPSS Score
0.029
Published
2022-10-29
In curl before 7.86.0, the HSTS check could be bypassed to trick it into staying with HTTP. Using its HSTS support, curl can be instructed to use HTTPS directly (instead of using an insecure cleartext HTTP step) even when HTTP is provided in the URL. This mechanism could be bypassed if the host name in the given URL uses IDN characters that get replaced with ASCII counterparts as part of the IDN conversion, e.g., using the character UTF-8 U+3002 (IDEOGRAPHIC FULL STOP) instead of the common ASCII full stop of U+002E (.). The earliest affected version is 7.77.0 2021-05-26.
CVSS Score
7.5
EPSS Score
0.016
Published
2022-10-29
When curl is used to retrieve and parse cookies from a HTTP(S) server, itaccepts cookies using control codes that when later are sent back to a HTTPserver might make the server return 400 responses. Effectively allowing a"sister site" to deny service to all siblings.
CVSS Score
3.7
EPSS Score
0.019
Published
2022-09-23
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.
CVSS Score
4.3
EPSS Score
0.271
Published
2022-07-07
curl < 7.84.0 supports "chained" HTTP compression algorithms, meaning that a serverresponse can be compressed multiple times and potentially with different algorithms. The number of acceptable "links" in this "decompression chain" was unbounded, allowing a malicious server to insert a virtually unlimited number of compression steps.The use of such a decompression chain could result in a "malloc bomb", makingcurl end up spending enormous amounts of allocated heap memory, or trying toand returning out of memory errors.
CVSS Score
6.5
EPSS Score
0.322
Published
2022-07-07
When curl < 7.84.0 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 file name.In that rename operation, it might accidentally *widen* the permissions for the target file, leaving the updated file accessible to more users than intended.
CVSS Score
9.8
EPSS Score
0.069
Published
2022-07-07
When curl < 7.84.0 does FTP transfers secured by krb5, it handles message verification failures wrongly. This flaw makes it possible for a Man-In-The-Middle attack to go unnoticed and even allows it to inject data to the client.
CVSS Score
5.9
EPSS Score
0.068
Published
2022-07-07
libcurl provides the `CURLOPT_CERTINFO` option to allow applications torequest details to be returned about a server's certificate chain.Due to an erroneous function, a malicious server could make libcurl built withNSS get stuck in a never-ending busy-loop when trying to retrieve thatinformation.
CVSS Score
7.5
EPSS Score
0.026
Published
2022-06-02
libcurl would reuse a previously created connection even when a TLS or SSHrelated option had been changed that should have prohibited reuse.libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse if one of them matches the setup. However, several TLS andSSH settings were left out from the configuration match checks, making themmatch too easily.
CVSS Score
7.5
EPSS Score
0.028
Published
2022-06-02