Vulnerability in Cisco routers versions 8.2 through 9.1 allows remote attackers to bypass access control lists when extended IP access list…

published 1992-12-10 33y ago modified 2026-06-16 4mo ago also EUVD-1999-1447

cvss: 7.5; version 2.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 2.3%; EPSS 2.3% chance of exploitation in 30 days, percentile 83%
public exploits: 0; none known

Vulnerability in Cisco routers versions 8.2 through 9.1 allows remote attackers to bypass access control lists when extended IP access lists are used on certain interfaces, the IP route cache is enabled, and the access list uses the "established" keyword.

Patch / fix

links 2

cert.org/advisories/CA-1992-20.html advisory
securityfocus.com/bid/53 advisory

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Exploit prediction

2.32% chance of exploitation in the next 30 days, higher than 83% of all scored CVEs (FIRST EPSS, 2026-11-14).

CVSS scores

assigned by	version	score	vector
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Technology feeds

Cisco IOS rss critical rss

References

cert.org /advisories/CA-1992-20.html
third-party-advisory, patch, us-government-resource
securityfocus.com /bid/53
vdb-entry, patch, vendor-advisory

Sources

CVE List CVE-1999-1466
NVD CVE-1999-1466

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