Medium · published November 18, 2025
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.
| Product | Versions | Fixed in |
|---|---|---|
| zyxel/lte3301-plus_firmware | ≤ 1.00\(abqu.7\)c0 | — |
| zyxel/nr5103_firmware | ≤ 4.19\(abyc.8\)c0 | — |
| zyxel/nr5103e_firmware | ≤ 1.00\(acdj.1\)c0 | — |
| zyxel/nr5309_firmware | ≤ 1.00\(ackp.1\)b3 | — |
| zyxel/nr7302_firmware | ≤ 5.00\(acha.5\)c0 | — |
| zyxel/nr7303_firmware | ≤ 1.00\(acei.1\)c0 | — |
| zyxel/nebula_fwa505_firmware | ≤ 1.19\(acko.0\)c0 | — |
| zyxel/nebula_fwa510_firmware | ≤ 1.20\(acgd.1\)c0 | — |
| zyxel/nebula_fwa515_firmware | ≤ 1.50\(acpz.0\)c0 | — |
| zyxel/nebula_fwa710_firmware | ≤ 1.20\(acgc.0\)c0 | — |
| zyxel/dm4200-b0_firmware | ≤ 5.17\(acbs.1.3\)c0 | — |
| zyxel/dx3300-t0_firmware | ≤ 5.50\(abvy.6.3\)c0 | — |
| zyxel/dx3300-t1_firmware | ≤ 5.50\(abvy.6.3\)c0 | — |
| zyxel/dx3301-t0_firmware | ≤ 5.50\(abvy.6.3\)c0 | — |
| zyxel/dx4510-b1_firmware | ≤ 5.17\(abyl.9\)c0 | — |
| zyxel/dx5401-b0_firmware | ≤ 5.17\(abyo.7\)b2 | — |
| zyxel/dx5401-b1_firmware | ≤ 5.17\(abyo.7\)b2 | — |
| zyxel/ee3301-00_firmware | ≤ 5.63\(acmu.1.1\)c0 | — |
| zyxel/ee5301-00_firmware | ≤ 5.63\(acld.1.1\)c0 | — |
| zyxel/ee6510-10_firmware | ≤ 5.19\(acjq.3\)c0 | — |
| zyxel/ex3300-t0_firmware | ≤ 5.50\(abvy.6.3\)c0 | — |
| zyxel/ex3300-t0_firmware | ≤ 5.50\(acdi.2.1\)c0 | — |
| zyxel/ex3300-t1_firmware | ≤ 5.50\(abvy.6.3\)c0 | — |
| zyxel/ex3301-t0_firmware | ≤ 5.50\(abvy.6.3\)c0 | — |
| zyxel/ex3500-t0_firmware | ≤ 5.44\(achr.4\)c0 | — |
| zyxel/ex3501-t0_firmware | ≤ 5.44\(achr.4\)c0 | — |
| zyxel/ex3600-t0_firmware | ≤ 5.70\(acif.1.2\)c0 | — |
| zyxel/ex5401-b0_firmware | ≤ 5.17\(abyo.7\)b2 | — |
| zyxel/ex5401-b1_firmware | ≤ 5.17\(abyo.7\)b2 | — |
| zyxel/ex5501-b0_firmware | ≤ 5.17\(abry.5.5\)c0 | — |
| zyxel/ex5510-b0_firmware | ≤ 5.17\(abqx.10\)c0 | — |
| zyxel/ex5512-t0_firmware | ≤ 5.70\(aceg.5\)c0 | — |
| zyxel/ex5601-t0_firmware | ≤ 5.70\(acdz.4.1\)c0 | — |
| zyxel/ex5601-t1_firmware | ≤ 5.70\(acdz.4.1\)c0 | — |
| zyxel/ex7501-b0_firmware | ≤ 5.18\(achn.2.1\)c0 | — |
| zyxel/ex7710-b0_firmware | ≤ 5.18\(acak.1.4\)c0 | — |
| zyxel/emg3525-t50b_firmware | ≤ 5.50\(abpm.9.5\)c0 | — |
| zyxel/emg5523-t50b_firmware | ≤ 5.50\(abpm.9.5\)c0 | — |
| zyxel/emg5723-t50k_firmware | ≤ 5.50\(abom.8.6\)c0 | — |
| zyxel/emg6726-b10a_firmware | ≤ 5.13\(abnp.8\)c0 | — |
| zyxel/gm4100-b0_firmware | ≤ 5.18\(accl.1\)c0 | — |
| zyxel/vmg3625-t50b_firmware | ≤ 5.50\(abpm.9.5\)c0 | — |
| zyxel/vmg3927-b50b_firmware | ≤ 5.13\(ably.10\)c0 | — |
| zyxel/vmg3927-t50k_firmware | ≤ 5.50\(abom.8.6\)c0 | — |
| zyxel/vmg4005-b50a_firmware | ≤ 5.17\(abqa.3\)c0 | — |
| zyxel/vmg4005-b60a_firmware | ≤ 5.17\(abqa.3\)c0 | — |
| zyxel/vmg4005-b50b_firmware | ≤ 5.13\(abrl.5.3\)c0 | — |
| zyxel/vmg4927-b50a_firmware | ≤ 5.13\(ably.10\)c0 | — |
| zyxel/vmg8623-t50b_firmware | ≤ 5.50\(abpm.9.5\)c0 | — |
| zyxel/vmg8825-t50k_firmware | ≤ 5.50\(abom.8.6\)c0 | — |
| zyxel/ax7501-b0_firmware | ≤ 5.17\(abpc.6.1\)c0 | — |
| zyxel/ax7501-b1_firmware | ≤ 5.17\(abpc.6.1\)c0 | — |
| zyxel/pe3301-00_firmware | ≤ 5.63\(acmt.1.1\)c0 | — |
| zyxel/pe5301-01_firmware | ≤ 5.63\(acoj.1.1\)c0 | — |
| zyxel/pm3100-t0_firmware | ≤ 5.42\(acbf.3\)c0 | — |
| zyxel/pm5100-t0_firmware | ≤ 5.42\(acbf.3\)c0 | — |
| zyxel/pm7500-00_firmware | ≤ 5.61\(ackk.1\)c0 | — |
| zyxel/pm7300-t0_firmware | ≤ 5.42\(abyy.3\)c0 | — |
| zyxel/px3321-t1_firmware | ≤ 5.44\(acjb.1.3\)c0 | — |
| zyxel/px3321-t1_firmware | ≤ 5.44\(achk.1\)c0 | — |
| zyxel/px5301-t0_firmware | ≤ 5.44\(ackb.0.4\)c0 | — |
| zyxel/scr_50axe_firmware | ≤ 1.10\(acgn.3\)c0 | — |
| zyxel/we3300-00_firmware | ≤ 5.70\(acka.0\)c0 | — |
| zyxel/wx3100-t0_firmware | ≤ 5.50\(abvl.4.7\)c0 | — |
| zyxel/wx3401-b0_firmware | ≤ 5.17\(abve.2.8\)c0 | — |
| zyxel/wx3401-b1_firmware | ≤ 5.17\(abve.2.8\)c0 | — |
| zyxel/wx5600-t0_firmware | ≤ 5.70\(aceb.4.1\)c0 | — |
| zyxel/wx5610-b0_firmware | ≤ 5.18\(acgj.0.3\)c0 | — |