CVE-2019-12524
This allows an attacker to encode their URL to bypass the url_regex check, and gain access to the blocked resource.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (4.25%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 4.25% probability · 90th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-306
- Affected
- squid-cache/squid · debian/debian linux · canonical/ubuntu linux
- Source
- cve@mitre.org
References
- https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12524.txtThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/07/msg00009.htmlMailing List, Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210205-0006/Third Party Advisory
- https://usn.ubuntu.com/4446-1/Third Party Advisory
- https://www.debian.org/security/2020/dsa-4682Third Party Advisory
- https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12524.txtThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/07/msg00009.htmlMailing List, Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210205-0006/Third Party Advisory
- https://usn.ubuntu.com/4446-1/Third Party Advisory
- https://www.debian.org/security/2020/dsa-4682Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.