Vulnerability Monitor

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CVE-2019-18677

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.

Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.1, indicating it can be exploited remotely over the network with relatively low complexity though user interaction is required and does not require pre-existing privileges . The vulnerability impacts limited data confidentiality, limited integrity, for affected systems. Impacting 3 products from squid-cache, from canonical, from fedoraproject organizations running these solutions should prioritize assessment and patching.

Historical Context

First disclosed in 2019, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.

Published

2019-11-26T17:15:12.923

Last Modified

2024-11-21T04:33:30.820

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 6.1 (MEDIUM)

CVSSv2 Vector

AV:N/AC:M/Au:N/C:P/I:P/A:N

Access Vector: NETWORK
Access Complexity: MEDIUM
Authentication: NONE
Confidentiality Impact: PARTIAL
Integrity Impact: PARTIAL
Availability Impact: NONE

Exploitability Score

8.6

Impact Score

4.9

Weaknesses

Type: Primary
CWE-352

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	squid-cache	squid	≤ 2.7	Yes
Application	squid-cache	squid	≤ 3.5.28	Yes
Application	squid-cache	squid	≤ 4.8	Yes
Application	squid-cache	squid	2.7	Yes
Application	squid-cache	squid	2.7	Yes
Application	squid-cache	squid	2.7	Yes
Application	squid-cache	squid	2.7	Yes
Application	squid-cache	squid	2.7	Yes
Application	squid-cache	squid	2.7	Yes
Application	squid-cache	squid	2.7	Yes
Application	squid-cache	squid	2.7	Yes
Operating System	canonical	ubuntu_linux	16.04	Yes
Operating System	canonical	ubuntu_linux	18.04	Yes
Operating System	canonical	ubuntu_linux	19.04	Yes
Operating System	canonical	ubuntu_linux	19.10	Yes
Operating System	fedoraproject	fedora	30	Yes
Operating System	fedoraproject	fedora	31	Yes

References

http://www.squid-cache.org/Advisories/SQUID-2019_9.txt Third Party Advisory ([email protected])
http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-e5f1813a674848dde570f7920873e1071f96e0b4.patch Release Notes ([email protected])
http://www.squid-cache.org/Versions/v4/changesets/squid-4-36492033ea4097821a4f7ff3ddcb971fbd1e8ba0.patch Release Notes ([email protected])
https://bugzilla.suse.com/show_bug.cgi?id=1156328 Issue Tracking, Third Party Advisory ([email protected])
https://github.com/squid-cache/squid/pull/427 Patch, Third Party Advisory ([email protected])
https://lists.debian.org/debian-lts-announce/2019/12/msg00011.html Third Party Advisory ([email protected])
https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html ([email protected])
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MTM74TU2BSLT5B3H4F3UDW53672NVLMC/ ([email protected])
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UEMOYTMCCFWK5NOXSXEIH5D2VGWVXR67/ ([email protected])
https://usn.ubuntu.com/4213-1/ Third Party Advisory ([email protected])
https://www.debian.org/security/2020/dsa-4682 ([email protected])
http://www.squid-cache.org/Advisories/SQUID-2019_9.txt Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-e5f1813a674848dde570f7920873e1071f96e0b4.patch Release Notes (af854a3a-2127-422b-91ae-364da2661108)
http://www.squid-cache.org/Versions/v4/changesets/squid-4-36492033ea4097821a4f7ff3ddcb971fbd1e8ba0.patch Release Notes (af854a3a-2127-422b-91ae-364da2661108)
https://bugzilla.suse.com/show_bug.cgi?id=1156328 Issue Tracking, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/squid-cache/squid/pull/427 Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://lists.debian.org/debian-lts-announce/2019/12/msg00011.html Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html (af854a3a-2127-422b-91ae-364da2661108)
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MTM74TU2BSLT5B3H4F3UDW53672NVLMC/ (af854a3a-2127-422b-91ae-364da2661108)
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UEMOYTMCCFWK5NOXSXEIH5D2VGWVXR67/ (af854a3a-2127-422b-91ae-364da2661108)
https://usn.ubuntu.com/4213-1/ Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.debian.org/security/2020/dsa-4682 (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For squid-cache's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.