Ubuntu Security Notice 5079-1 - It was discovered that curl incorrect handled memory when sending data to an MQTT server. A remote attacker could use this issue to cause curl to crash, resulting in a denial of service, or possibly execute arbitrary code. Patrick Monnerat discovered that curl incorrectly handled upgrades to TLS. When receiving certain responses from servers, curl would continue without TLS even when the option to require a successful upgrade to TLS was specified. Various other issues were also addressed.
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Ubuntu Security Notice USN-5079-1
September 15, 2021
curl vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 21.04
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
Summary:
Several security issues were fixed in curl.
Software Description:
- curl: HTTP, HTTPS, and FTP client and client libraries
Details:
It was discovered that curl incorrect handled memory when sending data to
an MQTT server. A remote attacker could use this issue to cause curl to
crash, resulting in a denial of service, or possibly execute arbitrary
code. (CVE-2021-22945)
Patrick Monnerat discovered that curl incorrectly handled upgrades to TLS.
When receiving certain responses from servers, curl would continue without
TLS even when the option to require a successful upgrade to TLS was
specified. (CVE-2021-22946)
Patrick Monnerat discovered that curl incorrectly handled responses
received before STARTTLS. A remote attacker could possibly use this issue
to inject responses and intercept communications. (CVE-2021-22947)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 21.04:
curl 7.74.0-1ubuntu2.3
libcurl3-gnutls 7.74.0-1ubuntu2.3
libcurl3-nss 7.74.0-1ubuntu2.3
libcurl4 7.74.0-1ubuntu2.3
Ubuntu 20.04 LTS:
curl 7.68.0-1ubuntu2.7
libcurl3-gnutls 7.68.0-1ubuntu2.7
libcurl3-nss 7.68.0-1ubuntu2.7
libcurl4 7.68.0-1ubuntu2.7
Ubuntu 18.04 LTS:
curl 7.58.0-2ubuntu3.15
libcurl3-gnutls 7.58.0-2ubuntu3.15
libcurl3-nss 7.58.0-2ubuntu3.15
libcurl4 7.58.0-2ubuntu3.15
In general, a standard system update will make all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-5079-1
CVE-2021-22945, CVE-2021-22946, CVE-2021-22947
Package Information:
https://launchpad.net/ubuntu/+source/curl/7.74.0-1ubuntu2.3
https://launchpad.net/ubuntu/+source/curl/7.68.0-1ubuntu2.7
https://launchpad.net/ubuntu/+source/curl/7.58.0-2ubuntu3.15