Huawei products NIP6800 versions V500R001C30, V500R001C60SPC500, and V500R005C00SPC100; Secospace USG6600 versions V500R001C30SPC600, V500R001C60SPC500, and V500R005C00SPC100; and USG9500 versions V500R001C30SPC600, V500R001C60SPC500, and V500R005C00SPC100 have a denial of service vulnerability. Attackers need to perform a series of operations in a special scenario to exploit this vulnerability. Successful exploit may cause the new connections can't be established, result in a denial of service.