SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2017-9334

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…

HIGH 7.5EPSS 1.55%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.55%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.55% probability · 75th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-20
Affected
call-cc/chicken
Source
cve@mitre.org
EPSS trend
0%3%5%27 October 2026: 1.55%27 October 202627 October 2026

EPSS 1.5% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.