CVE-2015-1820

REST client for Ruby (aka rest-client) before 1.8.0 allows remote attackers to conduct session fixation attacks or obtain sensitive cookie information by leveraging passage of cookies set in a response to a redirect.

Published: 2017-08-09 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2015-1820 is rated High Risk (71.3/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 4.35%). 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-2015-1820

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 3.72% 4.35% +0.62%
2 2025-10-08 3.96% 3.72% -0.24%
3 2025-03-30 — 3.96% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-1820

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-2015-1820

GitHub Security Advisory for CVE-2015-1820

GHSA-3fhf-6939-qg8p · Severity: critical · Ecosystem: rubygems — rest-client Gem Vulnerable to Session Fixation

OS Trackers for CVE-2015-1820

vendor priority summary link
debian not yet assigned CVE-2015-1820 not yet assigned priority: Debian including 1 source packages (ruby-rest-client), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2015-1820
redhat medium — https://access.redhat.com/security/cve/CVE-2015-1820
ubuntu medium CVE-2015-1820 medium priority: Ubuntu including 2 source packages (librestclient-ruby, ruby-rest-client), 28 status rows across 14 suites (artful, bionic, cosmic, disco, lucid, precise, trusty, upstream, utopic, vivid, wily, xenial, yakkety, zesty): DNE 14, not-affected 8, ignored 4, needs-triage 1, released 1. https://ubuntu.com/security/CVE-2015-1820

Affected software / configurations for CVE-2015-1820

Vendor Product Version Raw CPE
rest-client_project rest-client <= 1.7.3 cpe:2.3:a:rest-client_project:rest-client:*:*:*:*:*:ruby:*:*

References for CVE-2015-1820

URL Tags
http://www.openwall.com/lists/oss-security/2015/03/24/3 Mailing List VDB Entry
http://www.securityfocus.com/bid/73295 Third Party Advisory VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=1205291 Issue Tracking Patch Third Party Advisory VDB Entry
https://github.com/rest-client/rest-client/issues/369 Third Party Advisory
cvelogic Threat Intelligence