The OCSP functionality in stunnel before 4.24 does not properly search certificate revocation lists (CRL), which allows remote attackers to bypass intended access restrictions by using revoked certificates.
Conclusion & alert: CVE-2008-2420 is rated Moderate Risk (51.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.36%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
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 | 2026-06-15 | 0.49% | 1.36% | +0.88% |
| 2 | 2025-03-30 | 0.85% | 0.49% | -0.36% |
| 3 | 2025-03-29 | — | 0.85% | — |
Full EPSS history (10 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.8 | 2.0 | MEDIUM |
|
8.6 | 6.4 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
low | CVE-2008-2420 low priority: Debian including 1 source packages (stunnel4), 4 status rows across 4 suites (bookworm, bullseye, sid, trixie): resolved 4. | https://security-tracker.debian.org/tracker/CVE-2008-2420 |
gentoo
|
low | CVE-2008-2420: 1 GLSA(s) (200808-08), 1 atom(s) (net-misc/stunnel); latest impact low. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2008-2420 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2008-2420 |
ubuntu
|
medium | CVE-2008-2420 medium priority: Ubuntu including 1 source packages (stunnel4), 12 status rows across 12 suites (dapper, feisty, gutsy, hardy, intrepid, jaunty, karmic, lucid, maverick, natty, oneiric, upstream): not-affected 7, ignored 4, released 1. | https://ubuntu.com/security/CVE-2008-2420 |
Not vulnerable. OCSP protocol support was only implemented in upstream stunnel version 4.16. Therefore OCSP protocol is not available in the versions of stunnel as shipped with Red Hat Enterprise Linux 2.1, 3, 4, or 5.
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| stunnel | stunnel | 3.4a | cpe:2.3:a:stunnel:stunnel:3.4a:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.5 | cpe:2.3:a:stunnel:stunnel:3.5:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.6 | cpe:2.3:a:stunnel:stunnel:3.6:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.7 | cpe:2.3:a:stunnel:stunnel:3.7:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.8 | cpe:2.3:a:stunnel:stunnel:3.8:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.8p1 | cpe:2.3:a:stunnel:stunnel:3.8p1:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.8p2 | cpe:2.3:a:stunnel:stunnel:3.8p2:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.8p3 | cpe:2.3:a:stunnel:stunnel:3.8p3:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.8p4 | cpe:2.3:a:stunnel:stunnel:3.8p4:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.9 | cpe:2.3:a:stunnel:stunnel:3.9:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.10 | cpe:2.3:a:stunnel:stunnel:3.10:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.11 | cpe:2.3:a:stunnel:stunnel:3.11:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.12 | cpe:2.3:a:stunnel:stunnel:3.12:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.13 | cpe:2.3:a:stunnel:stunnel:3.13:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.14 | cpe:2.3:a:stunnel:stunnel:3.14:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.15 | cpe:2.3:a:stunnel:stunnel:3.15:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.16 | cpe:2.3:a:stunnel:stunnel:3.16:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.17 | cpe:2.3:a:stunnel:stunnel:3.17:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.18 | cpe:2.3:a:stunnel:stunnel:3.18:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.19 | cpe:2.3:a:stunnel:stunnel:3.19:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.20 | cpe:2.3:a:stunnel:stunnel:3.20:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.21 | cpe:2.3:a:stunnel:stunnel:3.21:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.21a | cpe:2.3:a:stunnel:stunnel:3.21a:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.21b | cpe:2.3:a:stunnel:stunnel:3.21b:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.21c | cpe:2.3:a:stunnel:stunnel:3.21c:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.22 | cpe:2.3:a:stunnel:stunnel:3.22:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.23 | cpe:2.3:a:stunnel:stunnel:3.23:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.24 | cpe:2.3:a:stunnel:stunnel:3.24:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.25 | cpe:2.3:a:stunnel:stunnel:3.25:*:*:*:*:*:*:* |
| stunnel | stunnel | 3.26 | cpe:2.3:a:stunnel:stunnel:3.26:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.00 | cpe:2.3:a:stunnel:stunnel:4.00:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.01 | cpe:2.3:a:stunnel:stunnel:4.01:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.02 | cpe:2.3:a:stunnel:stunnel:4.02:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.03 | cpe:2.3:a:stunnel:stunnel:4.03:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.04 | cpe:2.3:a:stunnel:stunnel:4.04:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.05 | cpe:2.3:a:stunnel:stunnel:4.05:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.06 | cpe:2.3:a:stunnel:stunnel:4.06:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.07 | cpe:2.3:a:stunnel:stunnel:4.07:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.08 | cpe:2.3:a:stunnel:stunnel:4.08:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.09 | cpe:2.3:a:stunnel:stunnel:4.09:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.10 | cpe:2.3:a:stunnel:stunnel:4.10:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.11 | cpe:2.3:a:stunnel:stunnel:4.11:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.12 | cpe:2.3:a:stunnel:stunnel:4.12:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.13 | cpe:2.3:a:stunnel:stunnel:4.13:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.14 | cpe:2.3:a:stunnel:stunnel:4.14:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.15 | cpe:2.3:a:stunnel:stunnel:4.15:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.16 | cpe:2.3:a:stunnel:stunnel:4.16:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.17 | cpe:2.3:a:stunnel:stunnel:4.17:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.18 | cpe:2.3:a:stunnel:stunnel:4.18:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.19 | cpe:2.3:a:stunnel:stunnel:4.19:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.20 | cpe:2.3:a:stunnel:stunnel:4.20:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.21 | cpe:2.3:a:stunnel:stunnel:4.21:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.22 | cpe:2.3:a:stunnel:stunnel:4.22:*:*:*:*:*:*:* |
| stunnel | stunnel | 4.23 | cpe:2.3:a:stunnel:stunnel:4.23:*:*:*:*:*:*:* |