Vulnerability Monitor

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CVE-2021-31806

An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a memory-management bug, it is vulnerable to a Denial of Service attack (against all clients using the proxy) via HTTP Range request processing.

Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 4 products from squid-cache, from debian, from fedoraproject and 1 other, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2021-05-27T13:15:08.270

Last Modified

2024-11-21T06:06:15.823

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 6.5 (MEDIUM)

CVSSv2 Vector

AV:N/AC:L/Au:S/C:N/I:N/A:P

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

Exploitability Score

8.0

Impact Score

2.9

Weaknesses

Type: Primary
CWE-116

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	squid-cache	squid	< 4.15	Yes
Application	squid-cache	squid	< 5.0.6	Yes
Operating System	debian	debian_linux	9.0	Yes
Operating System	debian	debian_linux	10.0	Yes
Operating System	fedoraproject	fedora	33	Yes
Operating System	fedoraproject	fedora	34	Yes
Application	netapp	cloud_manager	-	Yes

References

http://seclists.org/fulldisclosure/2023/Oct/14 Mailing List, Third Party Advisory ([email protected])
http://www.openwall.com/lists/oss-security/2023/10/11/3 Mailing List, Third Party Advisory ([email protected])
http://www.squid-cache.org/Versions/v4/changesets/squid-4-e7cf864f938f24eea8af0692c04d16790983c823.patch Patch, Vendor Advisory ([email protected])
https://github.com/squid-cache/squid/security/advisories/GHSA-pxwq-f3qr-w2xf Patch, Third Party Advisory ([email protected])
https://lists.debian.org/debian-lts-announce/2021/06/msg00014.html Mailing List, Third Party Advisory ([email protected])
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQ3U54ZCNXR44QRPW3AV2VCS6K3TKCF/ ([email protected])
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T4EPIWUZDJAXADDHVOPKRBTQHPBR6H66/ ([email protected])
https://security.netapp.com/advisory/ntap-20210716-0007/ Third Party Advisory ([email protected])
https://www.debian.org/security/2021/dsa-4924 Third Party Advisory ([email protected])
http://seclists.org/fulldisclosure/2023/Oct/14 Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
http://www.openwall.com/lists/oss-security/2023/10/11/3 Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
http://www.squid-cache.org/Versions/v4/changesets/squid-4-e7cf864f938f24eea8af0692c04d16790983c823.patch Patch, Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/squid-cache/squid/security/advisories/GHSA-pxwq-f3qr-w2xf Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://lists.debian.org/debian-lts-announce/2021/06/msg00014.html Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQ3U54ZCNXR44QRPW3AV2VCS6K3TKCF/ (af854a3a-2127-422b-91ae-364da2661108)
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T4EPIWUZDJAXADDHVOPKRBTQHPBR6H66/ (af854a3a-2127-422b-91ae-364da2661108)
https://security.netapp.com/advisory/ntap-20210716-0007/ Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.debian.org/security/2021/dsa-4924 Third Party Advisory (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.