CVE-2022-20708
CVE-2022-20708 is a security flaw in Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers, routers for small businesses. Attackers can run their own code on Cisco Small Business RV160, RV260, RV340, and RV345 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 2022.[1]
Cisco Small Business RV160, RV260, RV340, and RV345 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 small business RV series routers stack-based buffer overflow in Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers. In its words: “A vulnerability in Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers could allow an attacker to do any of the following: Execute arbitrary code elevate privileges, execute arbitrary commands, bypass authentication and authorization protections, fetch and run unsigned software, or cause a denial of service (DoS).”[1]
The CVE record adds: “Multiple vulnerabilities in Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers could allow an attacker to do any of the following: Execute arbitrary code Elevate privileges Execute arbitrary commands Bypass authentication and authorization protections Fetch and run unsigned software Cause denial of service (DoS) For more information about these vulnerabilities, see the Details section of this advisory.”[2]
The underlying weakness is stack buffer overflow (CWE-121), in MITRE’s list of common software weaknesses.
It scores 8.0 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 RV160, RV260, RV340, and RV345 Series Routers.
Most families won’t have Cisco Small Business RV160, RV260, RV340, and RV345 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 2022, 21 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 17 Mar 2022 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 15%. That’s in the top 4% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
Cisco has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Check whether you use it.Cisco Small Business RV160, RV260, RV340, and RV345 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 17 Mar 2022 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 8.0.[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 15%.[4] |
See also
Other Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers flaws
- CVE-2022-20703: small business RV series routers stack-based buffer overflow ·
- CVE-2022-20701: small business RV series routers stack-based buffer overflow ·
- CVE-2022-20700: small business RV series routers stack-based buffer overflow ·
- CVE-2022-20699: small business RV series routers stack-based buffer overflow ·
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 stack buffer overflow flaws
- CVE-2026-7273, Zyxel GS1900 Series Switches: stack-based buffer overflow ·
- CVE-2021-27137, DD-WRT: stack-based buffer overflow ·
- CVE-2025-53521, F5 BIG-IP: stack-based buffer overflow ·
- CVE-2025-42599, Qualitia Active! Mail: stack-based buffer overflow ·
- CVE-2025-22457, Ivanti Connect Secure, Policy Secure, and ZTA Gateways: stack-based buffer overflow ·
Added the same day
- CVE-2022-20703, Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers: small business RV series routers stack-based buffer overflow ·
- CVE-2022-20701, Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers: small business RV series routers stack-based buffer overflow ·
- CVE-2022-20700, Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers: small business RV series routers stack-based buffer overflow ·
- CVE-2022-20699, Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers: small business RV series routers stack-based buffer overflow ·
- CVE-2021-41379, Microsoft Windows: installer privilege escalation ·
Every Cisco flaw on CISA’s list · Everything added in March 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “Cisco Small Business RV Series Routers Stack-based Buffer Overflow Vulnerability”. Known Exploited Vulnerabilities Catalog, added 3 Mar 2022.
- ^ National Institute of Standards and Technology. “CVE-2022-20708 Detail”. National Vulnerability Database, published 10 Feb 2022.
- ^ Cisco. Advisories and fixes: tools.cisco.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.149, percentile 96.7, 31 Oct 2026.
- CVE Program. “CVE-2022-20708”. 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.