CVE-2021-27853 describes a medium-severity vulnerability (CVSS 4.7) affecting Layer 2 network filtering capabilities, including those in Cisco, IEEE, and IETF products. Attackers can bypass IPv6 RA guard or ARP inspection by manipulating VLAN 0 and LLC/SNAP headers, leading to potential information disclosure (I:L) and allowing for denial-of-service or man-in-the-middle attacks. While not actively exploited (KEV: No) and lacking public exploit code, the vulnerability has garnered significant community discussion and media coverage, indicating awareness within the cybersecurity landscape.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
<= 802.2h-1997CPE matchmatch criteria | cpe:2.3:a:ieee:ieee_802.2:*:*:*:*:*:*:*:* | ||
<= d1.0CPE matchmatch criteria | cpe:2.3:a:ietf:p802.1q:*:*:*:*:*:*:*:* | ||
15.5\(01.01.85\)sy07CPE matchmatch criteria | cpe:2.3:o:cisco:catalyst_6503-e_firmware:15.5\(01.01.85\)sy07:*:*:*:*:*:*:* | ||
15.5\(01.01.85\)sy07CPE matchmatch criteria | cpe:2.3:o:cisco:catalyst_6504-e_firmware:15.5\(01.01.85\)sy07:*:*:*:*:*:*:* | ||
15.5\(01.01.85\)sy07CPE matchmatch criteria | cpe:2.3:o:cisco:catalyst_6506-e_firmware:15.5\(01.01.85\)sy07:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.
The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.