CVE-2021-34730

highpriority · attend · 55EPSS 0.185 · 97 %ileexploit · PoCEURUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

1 exploit · PoC

Likely / severe?

18.5% (97th) EPSS

CVSS 10 · high

Is it mine?

11 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in the Universal Plug-and-Play (UPnP) service of Cisco Small Business RV110W, RV130, RV130W, and RV215W Routers could allow an unauthenticated, remote attacker to execute arbitrary code or cause an affected device to restart unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of incoming UPnP traffic. An attacker could exploit this vulnerability by sending a crafted UPnP request to an affected device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system or cause the device to reload, resulting in a DoS condition. Cisco has not released software updates that address this vulnerability.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedCisco Small Business RV Series Router Firmwarecisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

Technical severity, 0–10. One row per scoring source.

10.0

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 9.8–10

v2.010highAV:N/AC:L/Au:N/C:C/I:C/A:Cprimary · NVD / NIST USexploitability 10 · impact 10

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v3.19.8criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · psirt@cisco.com USexploitability 3.9 · impact 5.9

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Hsecondary · CVSS-BT (t0sche)

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · Cisco PSIRT US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-787USprimaryCWE-121USCWE-121US

exploits (1)

Public proof-of-concept and weaponised exploit code.

badmonkey7/CVE-2021-34730Cisco RV110w UPnP stack overflow PoC · poc_in_github

affected products (11)

Products and version ranges known to be affected.

Cisco Cisco Small Business RV Series Router Firmwareall versionscisco_csafUS
Cisco Cisco Small Business RV Series Router Firmware≤ n/aenisa_euvdEU
Cisco Systems Inc. Cisco RV130all versionsfstec_bduRU
Cisco Systems Inc. RV110W Wireless-N VPNall versionsfstec_bduRU
Cisco Systems Inc. RV130W Wireless-N Multifunction VPN Routerall versionsfstec_bduRU
Cisco Systems Inc. RV215W Wireless-N VPNall versionsfstec_bduRU
cisco application extension platform= 1.0.3.55nvdUScpe:2.3:a:cisco:application_extension_platform:*:*:*:*:*:*:*:*
cisco rv110w wireless-n vpn firewall firmwareall versionsnvdUScpe:2.3:o:cisco:rv110w_wireless-n_vpn_firewall_firmware:*:*:*:*:*:*:*:*
cisco rv130 vpn router firmwareall versionsnvdUScpe:2.3:o:cisco:rv130_vpn_router_firmware:*:*:*:*:*:*:*:*
cisco rv130w wireless-n multifunction vpn router firmwareall versionsnvdUScpe:2.3:o:cisco:rv130w_wireless-n_multifunction_vpn_router_firmware:*:*:*:*:*:*:*:*
cisco rv215w wireless-n vpn router firmwareall versionsnvdUScpe:2.3:o:cisco:rv215w_wireless-n_vpn_router_firmware:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

cisco-sa-cisco-sb-rv-overflow-htpymMB5Cisco Small Business RV110W, RV130, RV130W, and RV215W Routers Remote Command Execution and Denial of Service Vulnerability2021-08-18csaf · cisco_csafUS
A vulnerability in the Universal Plug-and-Play (UPnP) service of Cisco Small Business RV110W, RV130, RV130W, and RV215W Routers could allow an unauthenticated, remote attacker to execute arbitrary code or cause an affected device to restart unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of incoming UPnP traffic. An attacker could exploit this vulnerability by sending a crafted UPnP request to an affected device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system or cause the device to reload, resulting in a DoS condition. Cisco has not released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisco_csaf nvd NVD CVE.org MITRE

published 2021-08-18modified 2026-06-17

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+16120 more

references (4)

External citations — patches, advisories, analysis.

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