client_side_request.cc in Squid 3.2.x before 3.2.13 and 3.3.x before 3.3.8 allows remote attackers to cause a denial of service via a crafted port number in a HTTP Host header.
Conclusion & alert: CVE-2013-4123 is rated High Exploit Risk (68.5/100): CVSS Medium severity, with high exploitation likelihood (EPSS 68.92%, 99th percentile). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| 26886 | exploit_db | edb | 2013-07-16 | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-13 | 69.94% | 68.92% | -1.02% |
| 2 | 2026-03-20 | 74.31% | 69.94% | -4.38% |
| 3 | 2026-01-05 | — | 74.31% | — |
Full EPSS history (31 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2013-4123 unimportant priority: Debian including 1 source packages (squid), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2013-4123 |
gentoo
|
normal | CVE-2013-4123: 1 GLSA(s) (201309-22), 1 atom(s) (net-proxy/squid); latest impact normal. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2013-4123 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2013-4123 |
ubuntu
|
medium | CVE-2013-4123 medium priority: Ubuntu including 1 source packages (squid3), 5 status rows across 5 suites (lucid, precise, quantal, raring, upstream): not-affected 4, released 1. | https://ubuntu.com/security/CVE-2013-4123 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| squid-cache | squid | 3.3.0 | cpe:2.3:a:squid-cache:squid:3.3.0:*:*:*:*:*:*:* |
| squid-cache | squid | 3.3.0.2 | cpe:2.3:a:squid-cache:squid:3.3.0.2:*:*:*:*:*:*:* |
| squid-cache | squid | 3.3.0.3 | cpe:2.3:a:squid-cache:squid:3.3.0.3:*:*:*:*:*:*:* |
| squid-cache | squid | 3.3.1 | cpe:2.3:a:squid-cache:squid:3.3.1:*:*:*:*:*:*:* |
| squid-cache | squid | 3.3.2 | cpe:2.3:a:squid-cache:squid:3.3.2:*:*:*:*:*:*:* |
| squid-cache | squid | 3.3.3 | cpe:2.3:a:squid-cache:squid:3.3.3:*:*:*:*:*:*:* |
| squid-cache | squid | 3.3.4 | cpe:2.3:a:squid-cache:squid:3.3.4:*:*:*:*:*:*:* |
| squid-cache | squid | 3.3.5 | cpe:2.3:a:squid-cache:squid:3.3.5:*:*:*:*:*:*:* |
| squid-cache | squid | 3.3.6 | cpe:2.3:a:squid-cache:squid:3.3.6:*:*:*:*:*:*:* |
| squid-cache | squid | 3.3.7 | cpe:2.3:a:squid-cache:squid:3.3.7:*:*:*:*:*:*:* |
| opensuse | opensuse | 12.3 | cpe:2.3:o:opensuse:opensuse:12.3:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.1 | cpe:2.3:a:squid-cache:squid:3.2.0.1:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.2 | cpe:2.3:a:squid-cache:squid:3.2.0.2:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.3 | cpe:2.3:a:squid-cache:squid:3.2.0.3:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.4 | cpe:2.3:a:squid-cache:squid:3.2.0.4:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.5 | cpe:2.3:a:squid-cache:squid:3.2.0.5:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.6 | cpe:2.3:a:squid-cache:squid:3.2.0.6:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.7 | cpe:2.3:a:squid-cache:squid:3.2.0.7:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.8 | cpe:2.3:a:squid-cache:squid:3.2.0.8:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.9 | cpe:2.3:a:squid-cache:squid:3.2.0.9:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.10 | cpe:2.3:a:squid-cache:squid:3.2.0.10:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.11 | cpe:2.3:a:squid-cache:squid:3.2.0.11:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.12 | cpe:2.3:a:squid-cache:squid:3.2.0.12:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.13 | cpe:2.3:a:squid-cache:squid:3.2.0.13:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.14 | cpe:2.3:a:squid-cache:squid:3.2.0.14:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.15 | cpe:2.3:a:squid-cache:squid:3.2.0.15:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.16 | cpe:2.3:a:squid-cache:squid:3.2.0.16:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.17 | cpe:2.3:a:squid-cache:squid:3.2.0.17:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.18 | cpe:2.3:a:squid-cache:squid:3.2.0.18:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.0.19 | cpe:2.3:a:squid-cache:squid:3.2.0.19:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.1 | cpe:2.3:a:squid-cache:squid:3.2.1:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.2 | cpe:2.3:a:squid-cache:squid:3.2.2:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.3 | cpe:2.3:a:squid-cache:squid:3.2.3:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.4 | cpe:2.3:a:squid-cache:squid:3.2.4:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.5 | cpe:2.3:a:squid-cache:squid:3.2.5:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.6 | cpe:2.3:a:squid-cache:squid:3.2.6:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.7 | cpe:2.3:a:squid-cache:squid:3.2.7:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.8 | cpe:2.3:a:squid-cache:squid:3.2.8:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.9 | cpe:2.3:a:squid-cache:squid:3.2.9:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.10 | cpe:2.3:a:squid-cache:squid:3.2.10:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.11 | cpe:2.3:a:squid-cache:squid:3.2.11:*:*:*:*:*:*:* |
| squid-cache | squid | 3.2.12 | cpe:2.3:a:squid-cache:squid:3.2.12:*:*:*:*:*:*:* |