CVE-2015-8371

Exp

Composer before 2016-02-10 allows cache poisoning from other projects built on the same host. This results in attacker-controlled code entering a server-side build process. The issue occurs because of the way that dist packages are cached. The cache key is derived from the package name, the dist type, and certain other data from the package repository (which may simply be a commit hash, and thus can be found by an attacker). Versions through 1.0.0-alpha11 are affected, and 1.0.0 is unaffected.

Published: 2023-09-21 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2015-8371 is rated High Exploit Risk (75.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.74%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2015-8371

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2015-8371

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 2026-05-02 0.89% 0.74% -0.16%
2 2026-04-14 0.80% 0.89% +0.09%
3 2026-04-01 0.80%

Full EPSS history (45 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-8371

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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.
2.8 5.9 [email protected]

Weakness enumeration for CVE-2015-8371

GitHub Security Advisory for CVE-2015-8371

GHSA-725m-w832-q973 · Severity: high · Ecosystem: composer — Composer allows cache poisoning from other projects built on the same host

OS Trackers for CVE-2015-8371

vendor priority summary link
debian not yet assigned CVE-2015-8371 not yet assigned priority: Debian including 1 source packages (composer), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2015-8371
ubuntu medium CVE-2015-8371 medium priority: Ubuntu including 1 source packages (composer), 9 status rows across 9 suites (artful, bionic, precise, trusty, upstream, wily, xenial, yakkety, zesty): ignored 4, DNE 2, not-affected 2, released 1. https://ubuntu.com/security/CVE-2015-8371

Affected software / configurations for CVE-2015-8371

Vendor Product Version Raw CPE
getcomposer composer 1.0.0 cpe:2.3:a:getcomposer:composer:1.0.0:alpha1:*:*:*:*:*:*
getcomposer composer 1.0.0 cpe:2.3:a:getcomposer:composer:1.0.0:alpha10:*:*:*:*:*:*
getcomposer composer 1.0.0 cpe:2.3:a:getcomposer:composer:1.0.0:alpha11:*:*:*:*:*:*
getcomposer composer 1.0.0 cpe:2.3:a:getcomposer:composer:1.0.0:alpha2:*:*:*:*:*:*
getcomposer composer 1.0.0 cpe:2.3:a:getcomposer:composer:1.0.0:alpha3:*:*:*:*:*:*
getcomposer composer 1.0.0 cpe:2.3:a:getcomposer:composer:1.0.0:alpha4:*:*:*:*:*:*
getcomposer composer 1.0.0 cpe:2.3:a:getcomposer:composer:1.0.0:alpha5:*:*:*:*:*:*
getcomposer composer 1.0.0 cpe:2.3:a:getcomposer:composer:1.0.0:alpha6:*:*:*:*:*:*
getcomposer composer 1.0.0 cpe:2.3:a:getcomposer:composer:1.0.0:alpha7:*:*:*:*:*:*
getcomposer composer 1.0.0 cpe:2.3:a:getcomposer:composer:1.0.0:alpha8:*:*:*:*:*:*
getcomposer composer 1.0.0 cpe:2.3:a:getcomposer:composer:1.0.0:alpha9:*:*:*:*:*:*

References for CVE-2015-8371

cvelogic Threat Intelligence