CVE-2016-6286

The "spiffy-cgi-handlers" egg would convert a nonexistent "Proxy" header to the HTTP_PROXY environment variable, which would allow attackers to direct CGI programs which use this environment variable to use an attacker-specified HTTP proxy server (also known as a "httpoxy" attack). This affects all versions of spiffy-cgi-handlers before 0.5.

Published: 2017-01-10 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-6286 is rated Moderate Risk (55.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.48%). 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-2016-6286

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 0.70% 1.48% +0.78%
2 2025-03-30 0.78% 0.70% -0.08%
3 2025-03-29 — 0.78% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-6286

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-2016-6286

Affected software / configurations for CVE-2016-6286

Vendor Product Version Raw CPE
call-cc http-client <= 0.4.2 cpe:2.3:a:call-cc:http-client:*:*:*:*:*:*:*:*

References for CVE-2016-6286

URL Tags
http://lists.gnu.org/archive/html/chicken-announce/2016-07/msg00000.html Mitigation Third Party Advisory
http://www.securityfocus.com/bid/92105 Third Party Advisory VDB Entry
cvelogic Threat Intelligence