Talos Vulnerability Report

TALOS-2019-0837

Atlassian Jira issue attachment name information disclosure vulnerability

September 16, 2019
CVE Number

CVE-2019-14995

Summary

An issue attachment name information disclosure vulnerability exists in Atlassian Jira, from versions 7.6.4 to 8.1.0. Anonymous users can differentiate between valid attachment names and invalid attachment names for any given issue via /rest/api/1.0/render API endpoint.

Tested Versions

Atlassian Jira 7.6.4 Atlassian Jira 8.1.0

Product URLs

https://www.atlassian.com/software/jira

CVSSv3 Score

5.3 - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CWE

CWE-862 - Missing Authorization

Details

An attacker can use this vector to identify valid attachment names for any given issue. This does not require a valid session.

Exploit Proof-of-Concept

Submit a POST to /rest/api/1.0/render with the following body:

{"rendererType":"atlassian-wiki-renderer",
"unrenderedMarkup":"!<ATTACHMENT-NAME>!",
"issueKey":"<ISSUE-KEY>"}

replacing <ISSUE-KEY> with a valid issue key, and <ATTACHMENT-NAME> with a possibly valid attachment name.

A response containing "Unable to render embedded object..." indicates the filename is not valid for the issue.
A response containing "Unable to embed resource..." or a link to the file like ".../secure/attachment/..." indicates the filename is valid.

Timeline

2019-05-14 - Vendor Disclosure
2019-09-09 - Vendor Patched

2019-09-16 - Public Release

Credit

Discovered by Ben Taylor of Cisco ASIG.