CVE-2020-8286

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.

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.

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.

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.

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.

libcurl offers "OCSP stapling" via the CURLOPT_SSL_VERIFYSTATUS option. When set, libcurl verifies the OCSP response that a server responds with as part of the TLS handshake. It then aborts the TLS negotiation if something is wrong with the response. The same feature can be enabled with --cert-status using the curl tool.

As part of the OCSP response verification, a client should verify that the response is indeed set out for the correct certificate. This step was not performed by libcurl when built or told to use OpenSSL as TLS backend.

This flaw would allow an attacker, who perhaps could have breached a TLS server, to provide a fraudulent OCSP response that would appear fine, instead of the real one. Like if the original certificate actually has been revoked.

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:

• CVE-2020-8286: Fixed improper OSCP verification in the client side (bsc#1179593).
• CVE-2020-8285: Fixed a stack overflow due to FTP wildcard (bsc#1179399).
• CVE-2020-8284: Fixed an issue where a malicius FTP server could make curl connect to a different IP (bsc#1179398).

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

This update for curl fixes the following issues:

• CVE-2020-8286: Fixed improper OSCP verification in the client side (bsc#1179593).
• CVE-2020-8285: Fixed a stack overflow due to FTP wildcard (bsc#1179399).
• CVE-2020-8284: Fixed an issue where a malicius FTP server could make curl connect to a different IP (bsc#1179398).

This update was imported from the SUSE:SLE-15: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:

• CVE-2020-8286: Fixed improper OSCP verification in the client side (bsc#1179593).
• CVE-2020-8285: Fixed a stack overflow due to FTP wildcard (bsc#1179399).
• CVE-2020-8284: Fixed an issue where a malicius FTP server could make curl connect to a different IP (bsc#1179398).

This update for curl fixes the following issues:

• CVE-2020-8286: Fixed improper OSCP verification in the client side (bsc#1179593).
• CVE-2020-8285: Fixed a stack overflow due to FTP wildcard (bsc#1179399).
• CVE-2020-8284: Fixed an issue where a malicius FTP server could make curl connect to a different IP (bsc#1179398).

This update for curl fixes the following issues:

• CVE-2020-8286: Fixed improper OSCP verification in the client side (bsc#1179593).
• CVE-2020-8285: Fixed a stack overflow due to FTP wildcard (bsc#1179399).
• CVE-2020-8284: Fixed an issue where a malicius FTP server could make curl connect to a different IP (bsc#1179398).

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. 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)