CVE-2023-20118
CVE-2023-20118 is a security flaw in Cisco Small Business RV Series Routers, routers for small businesses. Attackers can run commands on Cisco Small Business RV Series Routers. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 3 Mar 2025.[1]
Cisco Small Business RV Series Routers is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Cisco has published a fix or advice.
Description
CISA calls it a command injection in Cisco Small Business RV Series Routers. In its words: “Multiple Cisco Small Business RV Series Routers contains a command injection vulnerability in the web-based management interface. Successful exploitation could allow an authenticated, remote attacker to gain root-level privileges and access unauthorized data.”[1]
The CVE record adds: “A vulnerability in the web-based management interface of Cisco Small Business Routers RV016, RV042, RV042G, RV082, RV320, and RV325 Routers could allow an authenticated, remote attacker to execute arbitrary commands on an affected device. This vulnerability is due to improper validation of user input within incoming HTTP packets. An attacker could exploit this vulnerability by sending a crafted HTTP request to the web-based management interface. A successful exploit could allow the attacker to gain root-level privileges and access unauthorized data. To exploit this vulnerability, an attacker would need to have valid administrative credentials on the affected device. Cisco has not and will not release software updates that address this vulnerability. However, administrators may disable the affected feature as described in the Workarounds ["#workarounds"]…”[2]
The underlying weakness is command injection (CWE-77), in MITRE’s list of common software weaknesses.
It scores 7.2 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Cisco’s advisory has them[3]. CISA names the product as Cisco Small Business RV Series Routers.
Most families won’t have Cisco Small Business RV Series Routers; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 3 Mar 2025, 690 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 24 Mar 2025 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 54%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Cisco has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.”[1]
- Check whether you use it.Cisco Small Business RV Series Routers is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 24 Mar 2025 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 7.2.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 54%.[4] |
See also
Other Cisco flaws
- CVE-2026-76418, Cisco Secure Firewall ASA Software and Cisco Secure FTD Software: unchecked return value to NULL pointer dereference ·
- CVE-2026-76519, Cisco Secure Email Gateway: relative path traversal ·
- CVE-2026-76504, Cisco Catalyst SD-WAN Manager: hex encoding ·
- CVE-2026-76460, Cisco Identity Services Engine: incorrect use of privileged APIs ·
- CVE-2026-76461, Cisco Secure Email Gateway: SQL injection ·
Other command injection flaws
- CVE-2026-105134, AhsayCBS: command injection ·
- CVE-2026-96951, Microsoft Windows: command injection ·
- CVE-2016-3081, Apache Struts: command injection ·
- CVE-2026-8037, Progress LoadMaster: command injection ·
- CVE-2025-29635, D-Link DIR-823X: command injection ·
Added the same day
- CVE-2024-4885, Progress WhatsUp Gold: path traversal ·
- CVE-2022-43939, Hitachi Vantara Pentaho Business Analytics (BA) Server: pentaho BA server authorization bypass ·
- CVE-2022-43769, Hitachi Vantara Pentaho Business Analytics (BA) Server: pentaho BA server special element injection ·
- CVE-2018-8639, Microsoft Windows: win32k improper resource shutdown or release ·
Every Cisco flaw on CISA’s list · Everything added in March 2025
References
- ^ Cybersecurity and Infrastructure Security Agency. “Cisco Small Business RV Series Routers Command Injection Vulnerability”. Known Exploited Vulnerabilities Catalog, added 3 Mar 2025.
- ^ National Institute of Standards and Technology. “CVE-2023-20118 Detail”. National Vulnerability Database, published 13 Apr 2023.
- ^ Cisco. Advisories and fixes: sec.cloudapps.cisco.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.541, percentile 99.0, 31 Oct 2026.
- CVE Program. “CVE-2023-20118”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.