An incorrect "pair?" check in the Scheme "length" procedure results in an unsafe pointer dereference in all CHICKEN Scheme versions prior to 4.13, which allows an attacker to cause a denial of service by passing an improper list to an application that calls "length" on it.
Conclusion & alert: CVE-2017-9334 is rated Moderate Risk (51.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.44%). 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 | 2025-11-21 | 0.33% | 0.44% | +0.10% |
| 2 | 2025-11-18 | 0.43% | 0.33% | -0.10% |
| 3 | 2025-03-30 | — | 0.43% | — |
Full EPSS history (8 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2017-9334: 1 source package rows (chicken); 7 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 0. | https://security.alpinelinux.org/vuln/CVE-2017-9334 |
debian
|
low | CVE-2017-9334 low priority: Debian including 1 source packages (chicken), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2017-9334 |
ubuntu
|
medium | CVE-2017-9334 medium priority: Ubuntu including 1 source packages (chicken), 22 status rows across 22 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial, yakkety, zesty): not-affected 16, ignored 3, DNE 1, needed 1, released 1. | https://ubuntu.com/security/CVE-2017-9334 |
| URL | Tags |
|---|---|
| http://lists.nongnu.org/archive/html/chicken-announce/2017-05/msg00000.html | Patch Third Party Advisory |
| http://lists.nongnu.org/archive/html/chicken-hackers/2017-05/msg00099.html | Patch Third Party Advisory |