CVE-2025-6599

An uncontrolled resource consumption vulnerability in the web server of Zyxel DX3301-T0 firmware version 5.50(ABVY.6.3)C0 and earlier could allow an attacker to perform Slowloris‑style denial‑of‑service (DoS) attacks. Such attacks may temporarily block legitimate HTTP requests and partially disrupt access to the web management interface, while other networking services remain unaffected. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

CVE-2025-6599 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

CVE-2025-6599 affects products from zyxel, specifically: ax7501-b0, ax7501-b0_firmware, ax7501-b1, ax7501-b1_firmware, dm4200-b0, dm4200-b0_firmware, dx3300-t0, dx3300-t0_firmware, dx3300-t1, dx3300-t1_firmware, dx3301-t0, dx3301-t0_firmware, dx4510-b1, dx4510-b1_firmware, dx5401-b0, dx5401-b0_firmware, dx5401-b1, dx5401-b1_firmware, ee3301-00, ee3301-00_firmware, ee5301-00, ee5301-00_firmware, ee6510-10, ee6510-10_firmware, emg3525-t50b, emg3525-t50b_firmware, emg5523-t50b, emg5523-t50b_firmware, emg5723-t50k, emg5723-t50k_firmware, emg6726-b10a, emg6726-b10a_firmware, ex3300-t0, ex3300-t0_firmware, ex3300-t1, ex3300-t1_firmware, ex3301-t0, ex3301-t0_firmware, ex3500-t0, ex3500-t0_firmware, ex3501-t0, ex3501-t0_firmware, ex3600-t0, ex3600-t0_firmware, ex5401-b0, ex5401-b0_firmware, ex5401-b1, ex5401-b1_firmware, ex5501-b0, ex5501-b0_firmware, ex5510-b0, ex5510-b0_firmware, ex5512-t0, ex5512-t0_firmware, ex5601-t0, ex5601-t0_firmware, ex5601-t1, ex5601-t1_firmware, ex7501-b0, ex7501-b0_firmware, ex7710-b0, ex7710-b0_firmware, gm4100-b0, gm4100-b0_firmware, lte3301-plus, lte3301-plus_firmware, nebula_fwa505, nebula_fwa505_firmware, nebula_fwa510, nebula_fwa510_firmware, nebula_fwa515, nebula_fwa515_firmware, nebula_fwa710, nebula_fwa710_firmware, nr5103, nr5103_firmware, nr5103e, nr5103e_firmware, nr5309, nr5309_firmware, nr7302, nr7302_firmware, nr7303, nr7303_firmware, pe3301-00, pe3301-00_firmware, pe5301-01, pe5301-01_firmware, pm3100-t0, pm3100-t0_firmware, pm5100-t0, pm5100-t0_firmware, pm7300-t0, pm7300-t0_firmware, pm7500-00, pm7500-00_firmware, px3321-t1, px3321-t1_firmware, px5301-t0, px5301-t0_firmware, scr_50axe, scr_50axe_firmware, vmg3625-t50b, vmg3625-t50b_firmware, vmg3927-b50b, vmg3927-b50b_firmware, vmg3927-t50k, vmg3927-t50k_firmware, vmg4005-b50a, vmg4005-b50a_firmware, vmg4005-b50b, vmg4005-b50b_firmware, vmg4005-b60a, vmg4005-b60a_firmware, vmg4927-b50a, vmg4927-b50a_firmware, vmg8623-t50b, vmg8623-t50b_firmware, vmg8825-t50k, vmg8825-t50k_firmware, we3300-00, we3300-00_firmware, wx3100-t0, wx3100-t0_firmware, wx3401-b0, wx3401-b0_firmware, wx3401-b1, wx3401-b1_firmware, wx5600-t0, wx5600-t0_firmware, wx5610-b0, wx5610-b0_firmware. Check the affected products table above for specific version ranges.

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.