CVE-2021-23270
CVE-2021-23270 is a high-severity vulnerability in Gargoyle-router Gargoyle with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-834.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v2: 4.3
- EPSS exploit prediction: 1% (60th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-834
- Affected product: Gargoyle-router Gargoyle
- Published:
- Last modified:
Description
In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set.
Frequently asked questions
- What is CVE-2021-23270?
- In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set.
- How severe is CVE-2021-23270?
- CVE-2021-23270 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2021-23270 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-23270?
- CVE-2021-23270 affects Gargoyle-router Gargoyle. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-23270?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-23270 published?
- CVE-2021-23270 was published on 2021-04-12 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:gargoyle-router:gargoyle:1.12.0:*:*:*:*:*:*:*
More vulnerabilities in Gargoyle-router Gargoyle
- CVE-2015-10145 — High (CVSS 8.8): Gargoyle router management utility versions 1.5.x contain an authenticated OS command execution vulnerability in…
All CVEs affecting Gargoyle-router Gargoyle →
Other CWE-834 (Excessive Iteration) vulnerabilities
- CVE-2017-12587 — High (CVSS 8.8): ImageMagick 7.0.6-1 has a large loop vulnerability in the ReadPWPImage function in coders\pwp.c.
- CVE-2025-62707 — High (CVSS 7.5): pypdf is a free and open-source pure-python PDF library. Prior to version 6.1.3, an attacker who uses this…
- CVE-2025-56571 — High (CVSS 7.5): Finance.js v4.1.0 contains a Denial of Service (DoS) vulnerability via the IRR function’s depth parameter. Improper…
- CVE-2024-4227 — High (CVSS 7.5): In Genivia gSOAP with a specific configuration an unauthenticated remote attacker can generate a high CPU load when…
- CVE-2023-49316 — High (CVSS 7.5): In Math/BinaryField.php in phpseclib 3 before 3.0.34, excessively large degrees can lead to a denial of service.
- CVE-2023-5632 — High (CVSS 7.5): In Eclipse Mosquito before and including 2.0.5, establishing a connection to the mosquitto server without sending data…