An issue was discovered in Squid before 4.10.
An issue was discovered in Squid before 4.10. Due to incorrect input validation, it can interpret crafted HTTP requests in unexpected ways to access server resources prohibited by earlier security filters.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for help- Published
- Feb 4, 2020
- Updated
- Jun 16, 2026
- EPSS
- 8.3% · 95th percentile
- CWE
- CWE-668
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Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 2 / 30 · 8.3%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| squid-cache | squid | cpe:2.3:a:squid-cache:squid |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| canonical | ubuntu linux | cpe:2.3:o:canonical:ubuntu_linux |
| opensuse | leap | cpe:2.3:o:opensuse:leap |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- canonical ubuntu linux16.04
- canonical ubuntu linux18.04
- canonical ubuntu linux19.10
- debian debian linux10.0
- debian debian linux9.0
- fedoraproject fedora30
- fedoraproject fedora31
- opensuse leap15.1
- squid-cache squidbefore 4.10
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | libecap | before 1.0.1-2.module_el8.6.0+2741+01592ae8 | 1.0.1-2.module_el8.6.0+2741+01592ae8 |
| AlmaLinux:8 | libecap-devel | before 1.0.1-2.module_el8.6.0+2741+01592ae8 | 1.0.1-2.module_el8.6.0+2741+01592ae8 |
| Alpine:v3.10 | squid | before 4.10-r0 | 4.10-r0 |
| Alpine:v3.8 | squid | before 3.5.27-r4 | 3.5.27-r4 |
| Debian:10 | squid | before 4.6-1+deb10u2 | 4.6-1+deb10u2 |
| Debian:12 | squid | before 4.10-1 | 4.10-1 |
| Debian:9 | squid3 | before 3.5.23-5+deb9u2 | 3.5.23-5+deb9u2 |
| openSUSE:Leap 15.1 | squid | before 4.10-lp151.2.14.1 | 4.10-lp151.2.14.1 |
| openSUSE:Leap 15.1 | squid | before 4.10-lp151.2.11.1 | 4.10-lp151.2.11.1 |
| Red Hat:enterprise_linux:7::server | squid | before 7:3.5.20-17.el7_9.4 | 7:3.5.20-17.el7_9.4 |
| Red Hat:enterprise_linux:7::server | squid-debuginfo | before 7:3.5.20-17.el7_9.4 | 7:3.5.20-17.el7_9.4 |
| Red Hat:enterprise_linux:7::server | squid-migration-script | before 7:3.5.20-17.el7_9.4 | 7:3.5.20-17.el7_9.4 |
| Red Hat:enterprise_linux:7::server | squid-sysvinit | before 7:3.5.20-17.el7_9.4 | 7:3.5.20-17.el7_9.4 |
| Red Hat:enterprise_linux:8::appstream | libecap | before 0:1.0.1-2.module+el8.1.0+4044+36416a77 | 0:1.0.1-2.module+el8.1.0+4044+36416a77 |
| Red Hat:enterprise_linux:8::appstream | libecap-debuginfo | before 0:1.0.1-2.module+el8.1.0+4044+36416a77 | 0:1.0.1-2.module+el8.1.0+4044+36416a77 |
| Red Hat:enterprise_linux:8::appstream | libecap-debugsource | before 0:1.0.1-2.module+el8.1.0+4044+36416a77 | 0:1.0.1-2.module+el8.1.0+4044+36416a77 |
| Red Hat:enterprise_linux:8::appstream | libecap-devel | before 0:1.0.1-2.module+el8.1.0+4044+36416a77 | 0:1.0.1-2.module+el8.1.0+4044+36416a77 |
| Red Hat:enterprise_linux:8::appstream | squid | before 7:4.11-3.module+el8.3.0+7851+7808b5f9 | 7:4.11-3.module+el8.3.0+7851+7808b5f9 |
| Red Hat:enterprise_linux:8::appstream | squid-debuginfo | before 7:4.11-3.module+el8.3.0+7851+7808b5f9 | 7:4.11-3.module+el8.3.0+7851+7808b5f9 |
| Red Hat:enterprise_linux:8::appstream | squid-debugsource | before 7:4.11-3.module+el8.3.0+7851+7808b5f9 | 7:4.11-3.module+el8.3.0+7851+7808b5f9 |
| Rocky Linux:8 | libecap | before 0:1.0.1-2.module+el8.4.0+404+316a0dc5 | 0:1.0.1-2.module+el8.4.0+404+316a0dc5 |
| SUSE:HPE Helion OpenStack 8 | squid | before 3.5.21-26.20.1 | 3.5.21-26.20.1 |
| SUSE:Linux Enterprise Module for Server Applications 15 SP1 | squid | before 4.10-5.14.1 | 4.10-5.14.1 |
| SUSE:Linux Enterprise Point of Sale 11 SP3 | squid3 | before 3.1.23-8.16.37.12.1 | 3.1.23-8.16.37.12.1 |
+1
Same product
squid-cache: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-46847Squid: denial of service in http digest authentication57Plan
- CVE-2024-25617Denial of Service in HTTP Header parser in squid proxy56Plan
- CVE-2023-49285Denial of Service in HTTP Message Processing in Squid56Plan
- CVE-2021-31806An issue was discovered in Squid before 4.15 and 5.x before 5.0.6.55Plan
- CVE-2020-8450An issue was discovered in Squid before 4.10.51Plan
- CVE-2024-25111SQUID-2024:1 Denial of Service in HTTP Chunked Decoding50Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| almalinux:libecap | 1.0.1-2.module_el8.6.0+2741+01592ae8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:libecap-devel | 1.0.1-2.module_el8.6.0+2741+01592ae8 · AlmaLinux:8 | Package registry (OSV) |
| alpine:squid | 4.10-r0 · Alpine:v3.10 | Package registry (OSV) |
| debian:squid | 4.10-1 · Debian:12 | Package registry (OSV) |
| debian:squid3 | 3.5.23-5+deb9u2 · Debian:9 | Package registry (OSV) |
| opensuse:squid | 4.10-lp151.2.11.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| red hat:libecap | 0:1.0.1-2.module+el8.1.0+4044+36416a77 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:libecap-debuginfo | 0:1.0.1-2.module+el8.1.0+4044+36416a77 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:libecap-debugsource | 0:1.0.1-2.module+el8.1.0+4044+36416a77 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:libecap-devel | 0:1.0.1-2.module+el8.1.0+4044+36416a77 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:squid | 7:3.5.20-17.el7_9.4 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:squid-debuginfo | 7:3.5.20-17.el7_9.4 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:squid-debugsource | 7:4.11-3.module+el8.3.0+7851+7808b5f9 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:squid-migration-script | 7:3.5.20-17.el7_9.4 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| red hat:squid-sysvinit | 7:3.5.20-17.el7_9.4 · Red Hat:enterprise_linux:7::server | Package registry (OSV) |
| rocky linux:libecap | 0:1.0.1-2.module+el8.4.0+404+316a0dc5 · Rocky Linux:8 | Package registry (OSV) |
| suse:squid | 4.10-4.6.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:squid3 | 3.1.23-8.16.37.12.1 · SUSE:Linux Enterprise Point of Sale 11 SP3 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-668 · Exposure of Resource to Wrong SphereCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- lists.opensuse.org/opensuse-security-announce/2020-03/msg00012.html
- lists.opensuse.org/opensuse-security-announce/2020-05/msg00010.html
- www.squid-cache.org/Advisories/SQUID-2020_1.txt
- www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-2020_1.patch
- www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-8e657e835965c3a011375feaa0359921c5b3e2dd.patch
- www.squid-cache.org/Versions/v4/changesets/SQUID-2020_1.patch
- www.squid-cache.org/Versions/v4/changesets/squid-4-b3a0719affab099c684f1cd62b79ab02816fa962.patch
- www.squid-cache.org/Versions/v4/changesets/squid-4-d8e4715992d0e530871519549add5519cbac0598.patch
- lists.debian.org/debian-lts-announce/2020/07/msg00009.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/G6W2IQ7QV2OGREFFUBNVZIDD3RJBDE4R/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TSU6SPANL27AGK5PCGBJOKG4LUWA555J/
- security.gentoo.org/glsa/202003-34
- security.netapp.com/advisory/ntap-20210304-0002/
- usn.ubuntu.com/4289-1/
- www.debian.org/security/2020/dsa-4682
Vendor advisories and official records. Exploit/PoC links are deliberately left out.