CVE-2019-18677

Description

An issue was discovered in Squid 3.x and 4.x through 4.8 when the append_domain setting is used (because the appended characters do not properly interact with hostname length restrictions). Due to incorrect message processing, it can inappropriately redirect traffic to origins it should not be delivered to.

Category

6.1
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 4.94% Top 15%
Vendor Advisory ubuntu.com Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory debian.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://github.com/squid-cache/squid/pull/427 third party advisory patch
https://bugzilla.suse.com/show_bug.cgi?id=1156328 issue tracking third party advisory
http://www.squid-cache.org/Advisories/SQUID-2019_9.txt third party advisory
http://www.squid-cache.org/Versions/v4/changesets/squid-4-36492033ea4097821a4f7ff3ddcb971fbd1e8ba0.patch release notes
http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-e5f1813a674848dde570f7920873e1071f96e0b4.patch release notes
https://usn.ubuntu.com/4213-1/ third party advisory vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UEMOYTMCCFWK5NOXSXEIH5D2VGWVXR67/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MTM74TU2BSLT5B3H4F3UDW53672NVLMC/ vendor advisory
https://lists.debian.org/debian-lts-announce/2019/12/msg00011.html third party advisory mailing list
https://www.debian.org/security/2020/dsa-4682 vendor advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html mailing list

Frequently Asked Questions

What is the severity of CVE-2019-18677?
CVE-2019-18677 has been scored as a medium severity vulnerability.
How to fix CVE-2019-18677?
To fix CVE-2019-18677, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2019-18677 being actively exploited in the wild?
It is possible that CVE-2019-18677 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~5% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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