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No exploitation reportedFix available

CVE-2020-11945

No exploitation reported by the sources we read.

  • Published2020-04-23
  • WeaknessCWE-190

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

An issue was discovered in Squid before 5.0.2. A remote attacker can replay a sniffed Digest Authentication nonce to gain access to resources that are otherwise forbidden. This occurs because the attacker can overflow the nonce reference counter (a short integer). Remote code execution may occur if the pooled token credentials are freed (instead of replayed as valid credentials).

Timeline

dates in UTC
  1. 2020-04-2315:15CVE publishedNVD
  2. 2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-11945?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-11945?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Canonical ubuntu linux
BranchAffectedFixed in
16.4= 16.04no fix published
18.4= 18.04no fix published
19.10= 19.10no fix published
20.4= 20.04no fix published
Fedoraproject fedora
BranchAffectedFixed in
30.x= 30no fix published
31.x= 31no fix published
32.x= 32no fix published
Squid-cache squid
BranchAffectedFixed in
5.0≥ 5.0, < 5.0.25.0.2
4.x≥ 4.0, < 4.114.11
3.x≥ 3.0, ≤ 3.5.28no fix published

2 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • libecapAlmaLinux:8all versions · fixed in 1.0.1-2.module_el8.6.0+2741+01592ae8and 1 other package

Full record on NVD

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVSS 3.19.8read 2026-10-23
  • NVDCVSS 2.07.5read 2026-10-23
  • NVDweakness (CWE)CWE-190read 2026-10-23
  • FIRST EPSSEPSS score27.2 %read 2026-10-23
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2020-04-23
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2020-11945?

An issue was discovered in Squid before 5.0.2. A remote attacker can replay a sniffed Digest Authentication nonce to gain access to resources that are otherwise forbidden. This occurs because the attacker can overflow the nonce reference counter (a short integer). Remote code execution may occur if the pooled token credentials are freed (instead of replayed as valid credentials).

Is CVE-2020-11945 actively exploited?

Active exploitation of CVE-2020-11945 has not been confirmed. Its EPSS score was 27.2% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-11945?

CVE-2020-11945 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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