CVE-2021-1229
CVE-2021-1229 is a medium-severity vulnerability in Cisco Nx-os with a CVSS 3.x base score of 5.8. 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-401.
Key facts
- Severity: Medium (CVSS 3.x base score 5.8)
- CVSS v2: 4.3
- EPSS exploit prediction: 1% (69th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-401
- Affected product: Cisco Nx-os
- Published:
- Last modified:
Description
A vulnerability in ICMP Version 6 (ICMPv6) processing in Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a slow system memory leak, which over time could lead to a denial of service (DoS) condition. This vulnerability is due to improper error handling when an IPv6-configured interface receives a specific type of ICMPv6 packet. An attacker could exploit this vulnerability by sending a sustained rate of crafted ICMPv6 packets to a local IPv6 address on a targeted device. A successful exploit could allow the attacker to cause a system memory leak in the ICMPv6 process on the device. As a result, the ICMPv6 process could run out of system memory and stop processing traffic. The device could then drop all ICMPv6 packets, causing traffic instability on the device. Restoring device functionality would require a device reboot.
Frequently asked questions
- What is CVE-2021-1229?
- A vulnerability in ICMP Version 6 (ICMPv6) processing in Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a slow system memory leak, which over time could lead to a denial of service (DoS) condition. This vulnerability is due to improper error handling when an IPv6-configured interface receives a specific type of ICMPv6 packet. An attacker could exploit this vulnerability by sending a sustained rate of crafted ICMPv6 packets to a local IPv6 address on a targeted device. A successful exploit could allow the attacker to cause a system memory leak in the ICMPv6 process on the device. As a result, the ICMPv6 process could run out of system memory and stop processing traffic. The device could then drop all ICMPv6 packets, causing traffic instability on the device. Restoring device functionality would require a device reboot.
- How severe is CVE-2021-1229?
- CVE-2021-1229 has a CVSS 3.x base score of 5.8, rated medium 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 low.
- Is CVE-2021-1229 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-1229?
- CVE-2021-1229 primarily affects Cisco Nx-os. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-1229?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2021-1229 published?
- CVE-2021-1229 was published on 2021-02-24 and last updated on 2026-06-17.
References
Affected products (3)
- cpe:2.3:o:cisco:nx-os:5.2\(1\)sv5\(1.3a\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:nx-os:8.4\(3.53\):*:*:*:*:*:*:*
- cpe:2.3:o:cisco:nx-os:15.1\(2.31\):*:*:*:*:*:*:*
More vulnerabilities in Cisco Nx-os
- CVE-2021-1361 — Critical (CVSS 9.8): A vulnerability in the implementation of an internal file management service for Cisco Nexus 3000 Series Switches and…
- CVE-2018-0310 — Critical (CVSS 9.8): A vulnerability in the Cisco Fabric Services component of Cisco FXOS Software and Cisco NX-OS Software could allow an…
- CVE-2018-0301 — Critical (CVSS 9.8): A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to craft…
- CVE-2016-1453 — Critical (CVSS 9.8): Buffer overflow in the Overlay Transport Virtualization (OTV) GRE feature in Cisco NX-OS 5.0 through 7.3 on Nexus 7000…
- CVE-2016-1341 — Critical (CVSS 9.8): Cisco NX-OS 7.0(1)N1(1), 7.0(1)N1(3), and 7.0(4)N1(1) on Nexus 2000 Fabric Extender devices has a blank root password,…
- CVE-2015-4235 — Critical (CVSS 9.0): Cisco Application Policy Infrastructure Controller (APIC) devices with software before 1.0(3o) and 1.1 before 1.1(1j)…
All CVEs affecting Cisco Nx-os →
Other CWE-401 (Missing Release of Memory after Effective Lifetime) vulnerabilities
- CVE-2026-46289 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: lib/scatterlist: fix length calculations in…
- CVE-2022-0742 — Critical (CVSS 9.1): Memory leak in icmp6 implementation in Linux Kernel 5.13+ allows a remote attacker to DoS a host by making it go…
- CVE-2024-25450 — High (CVSS 8.8): imlib2 v1.9.1 was discovered to mishandle memory allocation in the function init_imlib_fonts().
- CVE-2023-33718 — High (CVSS 8.8): mp4v2 v2.1.3 was discovered to contain a memory leak via MP4File::ReadString() at mp4file_io.cpp
- CVE-2021-40633 — High (CVSS 8.8): A memory leak (out-of-memory) in gif2rgb in util/gif2rgb.c in giflib 5.1.4 allows remote attackers trigger an out of…
- CVE-2021-3492 — High (CVSS 8.8): Shiftfs, an out-of-tree stacking file system included in Ubuntu Linux kernels, did not properly handle faults occurring…
Browse all CWE-401 (Missing Release of Memory after Effective Lifetime) vulnerabilities →