CVE-2020-24355
Zyxel VMG5313-B30B router on firmware 5.13(ABCJ.6)b3_1127, and possibly older versions of firmware are affected by insecure permissions which allows regular and other users to create new users with elevated privileges.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.18%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Zyxel VMG5313-B30B router on firmware 5.13(ABCJ.6)b3_1127, and possibly older versions of firmware are affected by insecure permissions which allows regular and other users to create new users with elevated privileges. This is done by changing "FirstIndex" field in JSON that is POST-ed during account creation. Similar may also be possible with account deletion.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.18% probability · 82th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-732
- Affected
- zyxel/vmg5313-b30b firmware
- Source
- cve@mitre.org
EPSS 2.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://blog.somegeneric.ninja/Zyxel_VMG5153_B30BExploit, Third Party Advisory
- https://blog.somegeneric.ninja/Zyxel_VMG5153_B30B_part2Exploit, Third Party Advisory
- https://www.zyxel.com/support/security_advisories.shtmlVendor Advisory
- https://blog.somegeneric.ninja/Zyxel_VMG5153_B30BExploit, Third Party Advisory
- https://blog.somegeneric.ninja/Zyxel_VMG5153_B30B_part2Exploit, Third Party Advisory
- https://www.zyxel.com/support/security_advisories.shtmlVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.