ALT-PU-2021-1178-2CVSS:3.x/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS:2.0/AV:N/AC:L/Au:N/C:N/I:N/A:CCVSS:3.x/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NCVSS:2.0/AV:N/AC:L/Au:N/C:N/I:C/A:NCVSS:3.x/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS:2.0/AV:N/AC:L/Au:N/C:N/I:N/A:CA security feature bypass vulnerability exists in the way Microsoft ASP.NET Core parses encoded cookie names.
The ASP.NET Core cookie parser decodes entire cookie strings which could allow a malicious attacker to set a second cookie with the name being percent encoded.
The security update addresses the vulnerability by fixing the way the ASP.NET Core cookie parser handles encoded names.
CVSS:2.0/AV:N/AC:L/Au:N/C:N/I:P/A:NCVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NCVSS:2.0/AV:N/AC:L/Au:N/C:N/I:N/A:PCVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS:2.0/AV:N/AC:L/Au:N/C:N/I:N/A:PCVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N