Information disclosure in firefox-esr (Alpine package)

1) Information disclosure

EUVDB-ID: #VU33439

Risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-11730

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.

A vulnerability exists where if a user opens a locally saved HTML file, this file can use file: URIs to access other files in the same directory or sub-directories if the names are known or guessed. The Fetch API can then be used to read the contents of any files stored in these directories and they may uploaded to a server. It was demonstrated that in combination with a popular Android messaging app, if a malicious HTML attachment is sent to a user and they opened that attachment in Firefox, due to that app's predictable pattern for locally-saved file names, it is possible to read attachments the victim received from other correspondents. This vulnerability affects Firefox ESR < 60.8, Firefox < 68, and Thunderbird < 60.8.

Mitigation

Install update from vendor's website.

Vulnerable software versions

firefox-esr (Alpine package): 60.7.2-r0

CPE2.3

• cpe:2.3:a:alpine:firefox-esr_alpine_package:60.7.2-r0:*:*:*:*:alpine_linux:*:3.9

External links

https://git.alpinelinux.org/aports/commit/?id=dbc43022e7aaaeb53d19f31c2ba03ab99f95c608
https://git.alpinelinux.org/aports/commit/?id=2619d83127353533f980218076d6c0c02fe7c198
https://git.alpinelinux.org/aports/commit/?id=a0c09e8b7fb341082bdaced72c40714ba91f932a

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.