An issue was discovered in Squid before 4.10.
Noroxi assessment
Priority: Plan (action score 51/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 71.7% (FIRST EPSS); higher than 99.4% of all records.
- 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.
- Fixed version: libecap (AlmaLinux:8) 1.0.1-2.module_el8.6.0+2741+01592ae8; libecap-devel (AlmaLinux:8) 1.0.1-2.module_el8.6.0+2741+01592ae8; squid (Alpine:v3.10) 4.10-r0.
- Mentioned 3 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Add it to your regular patch cycle. Upgrade to libecap (AlmaLinux:8) 1.0.1-2.module_el8.6.0+2741+01592ae8; libecap-devel (AlmaLinux:8) 1.0.1-2.module_el8.6.0+2741+01592ae8; squid (Alpine:v3.10) 4.10-r0 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
An issue was discovered in Squid before 4.10. Due to incorrect buffer management, a remote client can cause a buffer overflow in a Squid instance acting as a reverse proxy.
- Published
- Feb 4, 2020
- Updated
- Jun 16, 2026
- EPSS
- 71.7% · 99th percentile
- CWE
- CWE-131
Report tools
Action score
51
Plan
Add it to your regular patch cycle.
- CVSS
- 29 / 40 · 7.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 22 / 30 · 71.7%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| squid-cache | squid | cpe:2.3:a:squid-cache:squid |
| 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 |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
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
Published before and after this one in the same product
- ← EarlierCVE-2019-18679Nov 26, 2019 · An issue was discovered in Squid 2.x, 3.x, and 4.x through 4.8.42Plan
- ← EarlierCVE-2020-8449Feb 4, 2020 · An issue was discovered in Squid before 4.10.32Monitor
- Later →CVE-2020-8517Feb 4, 2020 · An issue was discovered in Squid before 4.10.32Monitor
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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-21-0448 · Jun 7, 2021(IBM Güvenlik Bülteni Yayınladı)
- TR-20-355 · May 18, 2020(Squid Sunucu Güvenlik Güncellemesi)
- TR-20-130 · Mar 5, 2020(Squid Sunucu Güvenlik Güncellemesi)
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
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- Low
Weakness class (CWE)
CWE-131 · Incorrect Calculation of Buffer SizeCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
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.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (14 more)Show less
- 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/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.