CVE-2020-8231

Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when sending data.

Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when sending data.

Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when sending data.

cURL is a computer software project providing a library (libcurl) and command-line tool (curl) for transferring data using various protocols.\r\n\r\n Security Fix(es):\r\n\r\n Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when sending data.(CVE-2020-8231)\r\n\r\n curl 7.41.0 through 7.73.0 is vulnerable to an improper check for certificate revocation due to insufficient verification of the OCSP response.(CVE-2020-8286)\r\n\r\n curl 7.21.0 to and including 7.73.0 is vulnerable to uncontrolled recursion due to a stack overflow issue in FTP wildcard match parsing.(CVE-2020-8285)\r\n\r\n 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.(CVE-2020-8284)\r\n\r\n

The curl packages provide the libcurl library and the curl utility for downloading files from servers using various protocols, including HTTP, FTP, and LDAP.

Security Fix(es):

• curl: FTP PASV command response can cause curl to connect to arbitrary host (CVE-2020-8284)

• curl: Malicious FTP server can trigger stack overflow when CURLOPT_CHUNK_BGN_FUNCTION is used (CVE-2020-8285)

• curl: Inferior OCSP verification (CVE-2020-8286)

• curl: Expired pointer dereference via multi API with CURLOPT_CONNECT_ONLY option set (CVE-2020-8231)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Rocky Linux 8.4 Release Notes linked from the References section.

Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when sending data.

An application that performs multiple requests with libcurl's multi API and sets the CURLOPT_CONNECT_ONLY option, might in rare circumstances experience that when subsequently using the setup connect-only transfer, libcurl picks and uses the wrong connection - and instead picks another one the application has created since then.

CURLOPT_CONNECT_ONLY is the option to tell libcurl to not perform an actual transfer, only connect. When that operation is completed, libcurl remembers which connection it used for that transfer and "easy handle". It remembers the connection using a pointer to the internal connectdata struct in memory.

If more transfers are then done with the same multi handle before the connect-only connection is used, leading to the initial connect-only connection to get closed (for example due to idle time-out) while also new transfers (and connections) are setup, such a new connection might end up getting the exact same memory address as the now closed connect-only connection.

If after those operations, the application then wants to use the original transfer's connect-only setup to for example use curl_easy_send() to send raw data over that connection, libcurl could erroneously find an existing connection still being alive at the address it remembered since before even though this is now a new and different connection.

The application could then accidentally send data over that connection which was not at all intended for that recipient, entirely unknowingly.

Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when sending data. (CVE-2020-8231).

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. (CVE-2020-8284).

curl 7.21.0 to and including 7.73.0 is vulnerable to uncontrolled recursion due to a stack overflow issue in FTP wildcard match parsing. (CVE-2020-8285).

curl 7.41.0 through 7.73.0 is vulnerable to an improper check for certificate revocation due to insufficient verification of the OCSP response. (CVE-2020-8286).

This update for curl fixes the following issues:

• An application that performs multiple requests with libcurl's multi API and sets the 'CURLOPT_CONNECT_ONLY' option, might in rare circumstances experience that when subsequently using the setup connect-only transfer, libcurl will pick and use the wrong connection and instead pick another one the application has created since then. [bsc#1175109, CVE-2020-8231]

This update was imported from the SUSE:SLE-15:Update update project.

This update for curl fixes the following issues:

• An application that performs multiple requests with libcurl's multi API and sets the 'CURLOPT_CONNECT_ONLY' option, might in rare circumstances experience that when subsequently using the setup connect-only transfer, libcurl will pick and use the wrong connection and instead pick another one the application has created since then. [bsc#1175109, CVE-2020-8231]

This update was imported from the SUSE:SLE-15-SP2:Update update project.

This update for curl fixes the following issues:

• An application that performs multiple requests with libcurl's multi API and sets the 'CURLOPT_CONNECT_ONLY' option, might in rare circumstances experience that when subsequently using the setup connect-only transfer, libcurl will pick and use the wrong connection and instead pick another one the application has created since then. [bsc#1175109, CVE-2020-8231]

This update was imported from the SUSE:SLE-15-SP2:Update update project.

These are all security issues fixed in the curl-7.79.1-1.1 package on the GA media of openSUSE Tumbleweed.

This update for curl fixes the following issues:

• An application that performs multiple requests with libcurl's multi API and sets the 'CURLOPT_CONNECT_ONLY' option, might in rare circumstances experience that when subsequently using the setup connect-only transfer, libcurl will pick and use the wrong connection and instead pick another one the application has created since then. [bsc#1175109, CVE-2020-8231]

This update for curl fixes the following issues:

• An application that performs multiple requests with libcurl's multi API and sets the 'CURLOPT_CONNECT_ONLY' option, might in rare circumstances experience that when subsequently using the setup connect-only transfer, libcurl will pick and use the wrong connection and instead pick another one the application has created since then. [bsc#1175109, CVE-2020-8231]

This update for curl fixes the following issues:

• An application that performs multiple requests with libcurl's multi API and sets the 'CURLOPT_CONNECT_ONLY' option, might in rare circumstances experience that when subsequently using the setup connect-only transfer, libcurl will pick and use the wrong connection and instead pick another one the application has created since then. [bsc#1175109, CVE-2020-8231]

This update for curl fixes the following issues:

• An application that performs multiple requests with libcurl's multi API and sets the 'CURLOPT_CONNECT_ONLY' option, might in rare circumstances experience that when subsequently using the setup connect-only transfer, libcurl will pick and use the wrong connection and instead pick another one the application has created since then. [bsc#1175109, CVE-2020-8231]

This update for curl fixes the following issues:

• CVE-2021-22898: TELNET stack contents disclosure (bsc#1186114)
• CVE-2021-22876: The automatic referer leaks credentials (bsc#1183933)
• CVE-2020-8286: Inferior OCSP verification (bsc#1179593)
• CVE-2020-8285: FTP wildcard stack overflow (bsc#1179399)
• CVE-2020-8284: Trusting FTP PASV responses (bsc#1179398)
• CVE-2020-8231: libcurl will pick and use the wrong connection with multiple requests with libcurl's multi API and the 'CURLOPT_CONNECT_ONLY' option (bsc#1175109)
• Fix: SFTP uploads result in empty uploaded files (bsc#1177976)

Marc Aldorasi discovered that curl incorrectly handled the libcurl CURLOPT_CONNECT_ONLY option. This could result in data being sent to the wrong destination, possibly exposing sensitive information.

USN-4466-1 fixed a vulnerability in curl. This update provides the corresponding update for Ubuntu 14.04 ESM.

Original advisory details:

Marc Aldorasi discovered that curl incorrectly handled the libcurl CURLOPT_CONNECT_ONLY option. This could result in data being sent to the wrong destination, possibly exposing sensitive information.

Marc Aldorasi discovered that curl incorrectly handled the libcurl CURLOPT_CONNECT_ONLY option. This could result in data being sent to the wrong destination, possibly exposing sensitive information. This issue only affected Ubuntu 20.10. (CVE-2020-8231)

Varnavas Papaioannou discovered that curl incorrectly handled FTP PASV responses. An attacker could possibly use this issue to trick curl into connecting to an arbitrary IP address and be used to perform port scanner and other information gathering. (CVE-2020-8284)

It was discovered that curl incorrectly handled FTP wildcard matchins. A remote attacker could possibly use this issue to cause curl to consume resources and crash, resulting in a denial of service. (CVE-2020-8285)

It was discovered that curl incorrectly handled OCSP response verification. A remote attacker could possibly use this issue to provide a fraudulent OCSP response. (CVE-2020-8286)