CVE-2009-2049: Cisco IOS

Medium severity, CVSS 5.4. EPSS: 2.4% chance of exploitation in the next 30 days.

Cisco IOS 12.0(32)S12 through 12.0(32)S13 and 12.0(33)S3 through 12.0(33)S4, 12.0(32)SY8 through 12.0(32)SY9, 12.2(33)SXI1 through 12.2(33)SXI2, 12.2XNC before 12.2(33)XNC2, 12.2XND before 12.2(33)XND1, and 12.4(24)T1; and IOS XE 2.3 through 2.3.1t and 2.4 through 2.4.0; when RFC4893 BGP routing is enabled, allows remote attackers to cause a denial of service (device reload) by using an RFC4271 peer to send a malformed update, aka Bug ID CSCta33973.

Affected products

• Cisco IOS: version 12.0(32)s12 only; version 12.0(32)s13 only; version 12.0(32)sy8 only; version 12.0(32)sy9 only; version 12.0(33)s3 only; version 12.0(33)s4 only; …
• Cisco IOS XE: version 2.3 only; version 2.3.1t only; version 2.4 only; version 2.4.0 only

Published 2009-07-30. Last modified 2026-06-16.