CVE-2021-33620: debian debian_linux Improper Input Validation
CVSS: 6.5v3.1MediumModified
AliasesALPINE-CVE-2021-33620UBUNTU-CVE-2021-33620DEBIAN-CVE-2021-33620openSUSE-SU-2024:11929-1
Published 28-05-2021Last modified 03-08-2024
Vulnerability summary
CVE-2021-33620 is a medium (CVSS 6.5) Improper Input Validation vulnerability in debian debian_linux. EPSS estimates a 79.58% chance of exploitation in the next 30 days, higher than 99.6% of scored vulnerabilities.
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)EPSS score
79.58%
0%100%
Critical · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 7 · Related 3Timeline
- 28-05-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server.
CVSS metrics
6 scores · 5 sources · 2 versionsMedium 6.5Preferred score · CVE.org (CNA)
CVSS:3.1/AC:L/AV:N/A:H/C:N/I:N/PR:L/S:U/UI:NSourcesAll 5 agree
- OSV · AlpineEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- NVDNIST6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Medium 4.0Preferred score · NVD (NIST)
AV:N/AC:L/Au:S/C:N/I:N/A:PSourcesSingle source
EPSS trend
Probability
79.58%
Chance of exploitation in the next 30 days
Percentile
100%
Versus all other CVEs
30-day change
0.00 pp
From 79.58% on 18-09-2026
18-09-202618-10-2026
EPSS score79.58%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian2 products
- squid< 4.13-10
- debian_linuxEOL9.0
Ubuntu2 products
- squid< 4.10-1ubuntu1.4
- squid3All versions (No fix recorded) | < 3.5.27-1ubuntu1.11
Alpine1 product
- squid≥ 5.0, < 5.0.6-r0
Fedoraproject1 product
- fedoraEOL33 | 34
Opensuse1 product
- squid&distro=openSUSE Tumbleweed< 5.4.1-2.1
Squid-cache1 product
- squid< 4.15 | ≥ 5.0, < 5.0.6
6 vendors · 8 products
References
14 links- www.squid-cache.org/Versions/v5/changesets/squid-5-8af775ed98bfd610f9ce762fe177e01b2675588c.patchMailing ListPatchVendor Advisory
- www.squid-cache.org/Versions/v4/changesets/squid-4-1e05a85bd28c22c9ca5d3ac9f5e86d6269ec0a8c.patchMailing ListPatchVendor Advisory
- lists.fedoraproject.org/archives/…Vendor Advisory
- lists.fedoraproject.org/archives/…Vendor Advisory
