CVE-2019-12524 Security feature bypass in n/a

What is CVE-2019-12524?

CVE-2019-12524 is a critical vulnerability in Canonical Ubuntu Linux, published on 15 Apr 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to see if the request should be denied. Squid by default comes with rules to block access to the Cache Manager, which serves detailed server information meant for the maintainer. This rule is implemented via url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to encode their URL to bypass the url_regex check, and gain access to the blocked resource.

Weakness: CWE-306

Which versions are affected by CVE-2019-12524?

It affects 3 products.

Products include Canonical Ubuntu Linux, Debian Debian Linux, Squid-Cache Squid.

How do I fix CVE-2019-12524?

Upgrade to a fixed version.

Is CVE-2019-12524 being exploited?

There is no known exploitation of CVE-2019-12524 in the wild and no public exploit code.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2019-12524, GHSA-wwv6-9vqw-fwxx, UBUNTU-CVE-2019-12524.