Curl Security Vulnerabilities
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...
6.2AI Score
0.0004EPSS
When a protocol selection parameter option disables all protocols without adding any then the default set of protocols would remain in the allowed set due to an error in the logic for removing protocols. The below command would perform a request to curl.se with a plaintext protocol which has been.....
6.2AI Score
0.0004EPSS
libcurl did not check the server certificate of TLS connections done to a host specified as an IP address, when built to use mbedTLS. libcurl would wrongly avoid using the set hostname function when the specified hostname was given as an IP address, therefore completely skipping the certificate...
5AI Score
0.0004EPSS
libcurl skips the certificate verification for a QUIC connection under certain conditions, when built to use wolfSSL. If told to use an unknown/bad cipher or curve, the error path accidentally skips the verification and returns OK, thus ignoring any certificate...
6.3AI Score
0.0004EPSS
curl inadvertently kept the SSL session ID for connections in its cache even when the verify status (OCSP stapling) test failed. A subsequent transfer to the same hostname could then succeed if the session ID cache was still fresh, which then skipped the verify status...
5.3CVSS
5.3AI Score
0.001EPSS
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...
5.3CVSS
5.7AI Score
0.001EPSS
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...
6.5CVSS
6.6AI Score
0.001EPSS
This flaw makes curl overflow a heap based buffer in the SOCKS5 proxy handshake. When curl is asked to pass along the host name to the SOCKS5 proxy to allow that to resolve the address instead of it getting done by curl itself, the maximum length that host name can be is 255 bytes. If the host...
9.8CVSS
9.6AI Score
0.003EPSS
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....
3.7CVSS
7AI Score
0.001EPSS
When curl retrieves an HTTP response, it stores the incoming headers so that they can be accessed later via the libcurl headers API. However, curl did not have a limit in how many or how large headers it would accept in a response, allowing a malicious server to stream an endless series of headers....
7.5CVSS
7.5AI Score
0.009EPSS
Integer overflow vulnerability in tool_operate.c in curl 7.65.2 via a large value as the retry delay. NOTE: many parties report that this has no direct security impact on the curl user; however, it may (in theory) cause a denial of service to associated systems or networks if, for example,...
3.3CVSS
4.1AI Score
0.0004EPSS
5.9CVSS
6.2AI Score
0.002EPSS
3.7CVSS
5.3AI Score
0.001EPSS
5.9CVSS
6.3AI Score
0.002EPSS
7.5CVSS
7.3AI Score
0.002EPSS
An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However, certai...
5.9CVSS
7.3AI Score
0.002EPSS
A vulnerability in input validation exists in curl <8.0 during communication using the TELNET protocol may allow an attacker to pass on maliciously crafted user name and "telnet options" during server negotiation. The lack of proper input scrubbing allows an attacker to send content or perform.....
8.8CVSS
8.8AI Score
0.002EPSS
A path traversal vulnerability exists in curl <8.0.0 SFTP implementation causes the tilde (~) character to be wrongly replaced when used as a prefix in the first path element, in addition to its intended use as the first element to indicate a path relative to the user's home directory. Attackers...
8.8CVSS
8.8AI Score
0.002EPSS
A double free vulnerability exists in libcurl <8.0.0 when sharing HSTS data between separate "handles". This sharing was introduced without considerations for do this sharing across separate threads but there was no indication of this fact in the documentation. Due to missing mutexes or thread.....
5.9CVSS
5.7AI Score
0.001EPSS
An authentication bypass vulnerability exists libcurl <8.0.0 in the connection reuse feature which can reuse previously established connections with incorrect user permissions due to a failure to check for changes in the CURLOPT_GSSAPI_DELEGATION option. This vulnerability affects...
5.9CVSS
7AI Score
0.002EPSS
An authentication bypass vulnerability exists in libcurl prior to v8.0.0 where it reuses a previously established SSH connection despite the fact that an SSH option was modified, which should have prevented reuse. libcurl maintains a pool of previously used connections to reuse them for subsequent....
5.5CVSS
7.1AI Score
0.0004EPSS
6.5CVSS
6.2AI Score
0.001EPSS
6.5CVSS
6.7AI Score
0.001EPSS
9.1CVSS
8.8AI Score
0.001EPSS
A use after free vulnerability exists in curl <7.87.0. Curl can be asked to tunnel virtually all protocols it supports through an HTTP proxy. HTTP proxies can (and often do) deny such tunnel operations. When getting denied to tunnel the specific protocols SMB or TELNET, curl would use a...
5.9CVSS
6.2AI Score
0.001EPSS
php-mod/curl (a wrapper of the PHP cURL extension) before 2.3.2 allows XSS via the post_file_path_upload.php key parameter and the POST data to...
6.1CVSS
5.9AI Score
0.001EPSS
A vulnerability exists in curl <7.87.0 HSTS check that could be bypassed to trick it to keep using HTTP. Using its HSTS support, curl can be instructed to use HTTPS instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. However, the HSTS mechanism could be...
7.5CVSS
7.3AI Score
0.001EPSS
curl can be told to parse a .netrc file for credentials. If that file endsin a line with 4095 consecutive non-white space letters and no newline, curlwould first read past the end of the stack-based buffer, and if the readworks, write a zero byte beyond its boundary.This will in most cases cause a....
6.5CVSS
7.5AI Score
0.002EPSS
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...
9.8CVSS
8.6AI Score
0.007EPSS
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...
8.1CVSS
8.9AI Score
0.009EPSS
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...
7.5CVSS
8.3AI Score
0.002EPSS
lib/curl.rb in the Curl Gem for Ruby allows remote attackers to execute arbitrary commands via shell metacharacters in a...
7.7AI Score
0.009EPSS
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...
3.7CVSS
4.7AI Score
0.001EPSS
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...
5.9CVSS
7.4AI Score
0.003EPSS
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 t...
9.8CVSS
8.9AI Score
0.003EPSS
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....
6.5CVSS
7.9AI Score
0.002EPSS
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 larg...
4.3CVSS
6.2AI Score
0.003EPSS
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....
4.3CVSS
5.4AI Score
0.001EPSS
The curl URL parser wrongly accepts percent-encoded URL separators like '/'when decoding the host name part of a URL, making it a different URL usingthe wrong host name when it is later retrieved.For example, a URL like http://example.com%2F127.0.0.1/, would be allowed bythe parser and get...
7.5CVSS
7.2AI Score
0.001EPSS
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.....
7.5CVSS
7.8AI Score
0.002EPSS
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 Listawareness. If PSL support not provided, a more rudimentary check.....
5.3CVSS
6.1AI Score
0.001EPSS
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...
7.5CVSS
7.4AI Score
0.002EPSS
A insufficiently protected credentials vulnerability in fixed in curl 7.83.0 might leak authentication or cookie header data on HTTP redirects to the same host but another port...
6.5CVSS
7.3AI Score
0.003EPSS
A use of incorrectly resolved name vulnerability fixed in 7.83.1 might remove the wrong file when --no-clobber is used together with...
8.1CVSS
7.8AI Score
0.002EPSS
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....
5.7CVSS
6.7AI Score
0.002EPSS
An information disclosure vulnerability exists in curl 7.65.0 to 7.82.0 are vulnerable that by using an IPv6 address that was in the connection pool but with a different zone id it could reuse a connection...
7.5CVSS
7.1AI Score
0.002EPSS
An improper authentication vulnerability exists in curl 7.33.0 to and including 7.82.0 which might allow reuse OAUTH2-authenticated connections without properly making sure that the connection was authenticated with the same credentials as set for this transfer. This affects SASL-enabled...
8.1CVSS
8AI Score
0.002EPSS
A user can tell curl >= 7.20.0 and <= 7.78.0 to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server (--ssl-reqd on the command line orCURLOPT_USE_SSL set to CURLUSESSL_CONTROL or CURLUSESSL_ALL withlibcurl). This requirement could be bypassed if the server would r...
7.5CVSS
7.6AI Score
0.003EPSS
When curl >= 7.20.0 and <= 7.78.0 connects to an IMAP or POP3 server to retrieve data using STARTTLS to upgrade to TLS security, the server can respond and send back multiple responses at once that curl caches. curl would then upgrade to TLS but not flush the in-queue of cached responses but....
5.9CVSS
7AI Score
0.001EPSS
When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it...
9.1CVSS
8.9AI Score
0.007EPSS