CVE-2015-2311

Integer underflow in Sandstorm Cap'n Proto before 0.4.1.1 and 0.5.x before 0.5.1.1 might allow remote peers to cause a denial of service or possibly obtain sensitive information from memory or execute arbitrary code via a crafted message.

Published: 2017-08-09 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2015-2311 is rated High Risk (66/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 0.98%). Mandatory action: High exploitation likelihood—assess exposure and prioritize 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-2015-2311

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 2026-04-12 1.05% 0.98% -0.07%
2 2025-03-30 2.92% 1.05% -1.86%
3 2025-03-29 2.92%

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-2311

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P 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:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 6.4 [email protected]

Weakness enumeration for CVE-2015-2311

OS Trackers for CVE-2015-2311

vendor priority summary link
debian not yet assigned CVE-2015-2311 not yet assigned priority: Debian including 1 source packages (capnproto), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2015-2311
ubuntu medium CVE-2015-2311 medium priority: Ubuntu including 1 source packages (capnproto), 10 status rows across 10 suites (artful, bionic, lucid, precise, trusty, upstream, wily, xenial, yakkety, zesty): not-affected 5, DNE 2, released 2, ignored 1. https://ubuntu.com/security/CVE-2015-2311

Affected software / configurations for CVE-2015-2311

Vendor Product Version Raw CPE
capnproto capnproto <= 0.4.1.0 cpe:2.3:a:capnproto:capnproto:*:*:*:*:*:*:*:*
capnproto capnproto 0.5.0.0 cpe:2.3:a:capnproto:capnproto:0.5.0.0:*:*:*:*:*:*:*
capnproto capnproto 0.5.1.0 cpe:2.3:a:capnproto:capnproto:0.5.1.0:*:*:*:*:*:*:*

References for CVE-2015-2311

cvelogic Threat Intelligence