#VU7836 Out-of-bounds read in Mozilla Firefox - CVE-2017-7753

Vulnerability identifier: #VU7836

Vulnerability risk: Low

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:Clear]

CVE-ID: CVE-2017-7753

CWE-ID: CWE-125

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers

Vendor: Mozilla

Description
The vulnerability allows a remote attacker to obtain potentially sensitive information on the target system.

The weakness exists due to out-of-bounds read when applying style rules to pseudo-elements, such as ::first-line, using cached style data. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and read arbitrary files on the system.

Successful exploitation of the vulnerability results in information disclosure.

Mitigation
Update to version 55.0.

Vulnerable software versions

Mozilla Firefox: 45.0 - 54.0

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External links
https://www.mozilla.org/en-US/security/advisories/mfsa2017-18/

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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.