Exposure of Sensitive Information to an Unauthorized Actor in activestorage

published 2018-11-30 7 y ago modified 2026-06-17 4 mo ago also GHSA-7rr7-rcjw-56vj , EUVD-2018-0801

cvss: 6.5; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.3%; EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits: 0; none known

A bypass vulnerability in Active Storage >= 5.2.0 for Google Cloud Storage and Disk services allow an attacker to modify the `content-disposition` and `content-type` parameters which can be used in with HTML files and have them executed inline. Additionally, if combined with other techniques such as cookie bombing and specially crafted AppCache manifests, an attacker can gain access to private signed URLs within a specific storage path. This vulnerability has been fixed in version 5.2.1.1.

Patch / fix

fixed in 2 distros 1

rubygems activestorage 5.2.1.1
rubyonrails rails 5.2.1.1

rails Debian 14, Debian 13, Debian 12 2:5.2.2+dfsg-1

debian advisories DEBIAN-CVE-2018-16477

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-16477 updated 2025-11-21 cvss 6.5

rubygem-activestorage: bypass vulnerability in Google Cloud Storage and Disk services

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.31% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

groups.google.com https://groups.google.com/d/msg/rubyonrails-security/3KQRnXDIuLg/mByx5KkqBAAJ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.0	6.5	CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N
GitHub	3.0	6.5	CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
rubygems	activestorage	>=5.2.0, <5.2.1.1	5.2.1.1

Affected products

n/a https://github.com/rails/rails

Classification

Weakness

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

Technology feeds

Ruby on Rails rss critical rss

References

groups.google.com /d/msg/rubyonrails-security/3KQRnXDIuLg/mByx5KkqBAAJ
web, exploit, mailing-list, mitigation, third-party-advisory
weblog.rubyonrails.org /2018/11/27/Rails-4-2-5-0-5-1-5-2-have-been-released/
vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2018-16477
advisory
github.com /advisories/GHSA-7rr7-rcjw-56vj
advisory
weblog.rubyonrails.org /2018/11/27/Rails-4-2-5-0-5-1-5-2-have-been-released
web

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary