9.3 High
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:C/I:C/A:C
0.974 High
EPSS
Percentile
99.9%
This vulnerability allows attackers to execute arbitrary code on vulnerable installations of the Mozilla/Firefox web browser and Thunderbird e-mail client. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious e-mail. The specific flaw is due to incorrect handling of the CSS “letter-spacing” element. By specifying a large number, an attacker can overflow an integer used during memory allocation. The under-allocated buffer is later used to store user-supplied data leading to an exploitable heap overflow.