CVE-2017-11343

Due to an incomplete fix for CVE-2012-6125, all versions of CHICKEN Scheme up to and including 4.12.0 are vulnerable to an algorithmic complexity attack. An attacker can provide crafted input which, when inserted into the symbol table, will result in O(n) lookup time.

Published: 2017-07-17 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2017-11343 is rated Moderate Risk (50/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.35%). 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.

Exploit prediction scoring system (EPSS) score for CVE-2017-11343

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 2025-09-30 0.24% 0.35% +0.11%
2 2025-03-30 0.50% 0.24% -0.26%
3 2025-03-29 0.50%

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-11343

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2017-11343

OS Trackers for CVE-2017-11343

vendor priority summary link
debian not yet assigned CVE-2017-11343 not yet assigned 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-2017-11343
ubuntu low CVE-2017-11343 low 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-2017-11343

Affected software / configurations for CVE-2017-11343

Vendor Product Version Raw CPE
call-cc chicken <= 4.12.0 cpe:2.3:a:call-cc:chicken:*:*:*:*:*:*:*:*

References for CVE-2017-11343

cvelogic Threat Intelligence