CVE-2021-22925

curl supports the -t command line option, known as CURLOPT_TELNETOPTIONSin libcurl. This rarely used option is used to send variable=content pairs toTELNET servers.Due to flaw in the option parser for sending NEW_ENV variables, libcurlcould be made to pass on uninitialized data from a stack based buffer to theserver. Therefore potentially revealing sensitive internal information to theserver using a clear-text network protocol.This could happen because curl did not call and use sscanf() correctly whenparsing the string provided by the application.

curl supports the -t command line option, known as CURLOPT_TELNETOPTIONSin libcurl. This rarely used option is used to send variable=content pairs toTELNET servers.Due to flaw in the option parser for sending NEW_ENV variables, libcurlcould be made to pass on uninitialized data from a stack based buffer to theserver. Therefore potentially revealing sensitive internal information to theserver using a clear-text network protocol.This could happen because curl did not call and use sscanf() correctly whenparsing the string provided by the application.

cURL is a computer software project providing a library (libcurl) and command-line tool (curl) for transferring data using various protocols.

Security Fix(es):

curl supports the -t command line option, known as CURLOPT_TELNETOPTIONSin libcurl. This rarely used option is used to send variable=content pairs toTELNET servers.Due to flaw in the option parser for sending NEW_ENV variables, libcurlcould be made to pass on uninitialized data from a stack based buffer to theserver. Therefore potentially revealing sensitive internal information to theserver using a clear-text network protocol.This could happen because curl did not call and use sscanf() correctly whenparsing the string provided by the application.(CVE-2021-22925)

libcurl-using applications can ask for a specific client certificate to be used in a transfer. This is done with the CURLOPT_SSLCERT option (--cert with the command line tool).When libcurl is built to use the macOS native TLS library Secure Transport, an application can ask for the client certificate by name or with a file name - using the same option. If the name exists as a file, it will be used instead of by name.If the appliction runs with a current working directory that is writable by other users (like /tmp), a malicious user can create a file name with the same name as the app wants to use by name, and thereby trick the application to use the file based cert instead of the one referred to by name making libcurl send the wrong client certificate in the TLS connection handshake.(CVE-2021-22926)

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: Leak of authentication credentials in URL via automatic Referer (CVE-2021-22876)

• curl: TELNET stack contents disclosure (CVE-2021-22898)

• curl: Incorrect fix for CVE-2021-22898 TELNET stack contents disclosure (CVE-2021-22925)

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 8.5 Release Notes linked from the References section.

curl supports the -t command line option, known as CURLOPT_TELNETOPTIONSin libcurl. This rarely used option is used to send variable=content pairs toTELNET servers.Due to flaw in the option parser for sending NEW_ENV variables, libcurlcould be made to pass on uninitialized data from a stack based buffer to theserver. Therefore potentially revealing sensitive internal information to theserver using a clear-text network protocol.This could happen because curl did not call and use sscanf() correctly whenparsing the string provided by the application.

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: Leak of authentication credentials in URL via automatic Referer (CVE-2021-22876)

• curl: TELNET stack contents disclosure (CVE-2021-22898)

• curl: Incorrect fix for CVE-2021-22898 TELNET stack contents disclosure (CVE-2021-22925)

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 AlmaLinux Release Notes linked from the References section.

• telnet stack contents disclosure again (CVE-2021-22925)

• telnet stack contents disclosure again (CVE-2021-22925)

• telnet stack contents disclosure again (CVE-2021-22925)

• SECURITY UPDATE: TELNET stack contents disclosure again
  • debian/patches/CVE-2021-22925.patch: check sscanf() for correct number
  • of matches in lib/telnet.c
  • CVE-2021-22925

• CVE-2021-22925: fix TELNET stack contents disclosure again
• CVE-2021-22898: fix TELNET stack contents disclosure
• CVE-2021-22876: prevent automatic referer from leaking credentials

curl supports the -t command line option, known as CURLOPT_TELNETOPTIONS in libcurl. This rarely used option is used to send variable=content pairs to TELNET servers.

Due to flaw in the option parser for sending NEW_ENV variables, libcurl could be made to pass on uninitialized data from a stack based buffer to the server. Therefore potentially revealing sensitive internal information to the server using a clear-text network protocol.

This could happen because curl did not call and use sscanf() correctly when parsing the string provided by the application.

The previous curl security vulnerability CVE-2021-22898 is almost identical to this one but the fix was insufficient so this security vulnerability remained.

Wrong content via metalink not discarded (CVE-2021-22922).

Metalink download sends credentials (CVE-2021-22923).

Bad connection reuse due to flawed path name checks (CVE-2021-22924).

TELNET stack contents disclosure again (CVE-2021-22925).

This update for curl fixes the following issues:

• CVE-2021-22925: TELNET stack contents disclosure again. (bsc#1188220)
• CVE-2021-22924: Bad connection reuse due to flawed path name checks. (bsc#1188219)
• CVE-2021-22923: Insufficiently Protected Credentials. (bsc#1188218)
• CVE-2021-22922: Wrong content via metalink not discarded. (bsc#1188217)

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

This update for curl fixes the following issues:

• CVE-2021-22925: TELNET stack contents disclosure again. (bsc#1188220)
• CVE-2021-22924: Bad connection reuse due to flawed path name checks. (bsc#1188219)
• CVE-2021-22923: Insufficiently Protected Credentials. (bsc#1188218)
• CVE-2021-22922: Wrong content via metalink not discarded. (bsc#1188217)

This update for curl fixes the following issues:

• CVE-2021-22925: TELNET stack contents disclosure again. (bsc#1188220)
• CVE-2021-22924: Bad connection reuse due to flawed path name checks. (bsc#1188219)
• CVE-2021-22923: Insufficiently Protected Credentials. (bsc#1188218)
• CVE-2021-22922: Wrong content via metalink not discarded. (bsc#1188217)

This update for curl fixes the following issues:

• CVE-2021-22925: TELNET stack contents disclosure again. (bsc#1188220)
• CVE-2021-22924: Bad connection reuse due to flawed path name checks. (bsc#1188219)
• CVE-2021-22923: Insufficiently Protected Credentials. (bsc#1188218)
• CVE-2021-22922: Wrong content via metalink not discarded. (bsc#1188217)

This update for curl fixes the following issues:

• CVE-2021-22925: TELNET stack contents disclosure again. (bsc#1188220)
• CVE-2021-22924: Bad connection reuse due to flawed path name checks. (bsc#1188219)
• CVE-2021-22923: Insufficiently Protected Credentials. (bsc#1188218)
• CVE-2021-22922: Wrong content via metalink not discarded. (bsc#1188217)

This update for curl fixes the following issues:

• CVE-2021-22925: TELNET stack contents disclosure again. (bsc#1188220)
• CVE-2021-22924: Bad connection reuse due to flawed path name checks. (bsc#1188219)
• CVE-2021-22923: Insufficiently Protected Credentials. (bsc#1188218)
• CVE-2021-22922: Wrong content via metalink not discarded. (bsc#1188217)

This update for curl fixes the following issues:

• CVE-2021-22925: TELNET stack contents disclosure again. (bsc#1188220)
• CVE-2021-22924: Bad connection reuse due to flawed path name checks. (bsc#1188219)
• CVE-2021-22923: Insufficiently Protected Credentials. (bsc#1188218)
• CVE-2021-22922: Wrong content via metalink not discarded. (bsc#1188217)

Harry Sintonen and Tomas Hoger discovered that curl incorrectly handled TELNET connections when the -t option was used on the command line. Uninitialized data possibly containing sensitive information could be sent to the remote server, contrary to expectations. (CVE-2021-22898, CVE-2021-22925)

Harry Sintonen discovered that curl incorrectly reused connections in the connection pool. This could result in curl reusing the wrong connections. (CVE-2021-22924)

USN-5021-1 fixed vulnerabilities in curl. This update provides the corresponding updates for Ubuntu 16.04 ESM.

Original advisory details:

Harry Sintonen and Tomas Hoger discovered that curl incorrectly handled TELNET connections when the -t option was used on the command line. Uninitialized data possibly containing sensitive information could be sent to the remote server, contrary to expectations. (CVE-2021-22898, CVE-2021-22925)

Harry Sintonen and Tomas Hoger discovered that curl incorrectly handled TELNET connections when the -t option was used on the command line. Uninitialized data possibly containing sensitive information could be sent to the remote server, contrary to expectations. This issue was only fixed in Ubuntu 14.04 ESM. (CVE-2021-22898, CVE-2021-22925)

It was discovered that curl incorrectly handled denials when using HTTP proxies. A remote attacker could use this issue to cause curl to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2022-43552)