Vulnerability Database

393,544

Total vulnerabilities in the database

CVE-2009-2863 — cisco / ios

Improper Authentication

Race condition in the Firewall Authentication Proxy feature in Cisco IOS 12.0 through 12.4 allows remote attackers to bypass authentication, or bypass the consent web page, via a crafted request, aka Bug ID CSCsy15227.

  • Published: Sep 28, 2009
  • Updated: Oct 4, 2026
  • CVE: CVE-2009-2863
  • Severity: High
  • Exploit:
  • CISA KEV:

CVSS v2:

  • Severity: High
  • Score: 7.1
  • AV:N/AC:M/Au:N/C:C/I:N/A:N
Software Affected versions
cisco / ios = 12.0xk
cisco / ios = 12.0xr
cisco / ios = 12.1
cisco / ios = 12.1e
cisco / ios = 12.1ex
cisco / ios = 12.1t
cisco / ios = 12.1xc
cisco / ios = 12.1xh
cisco / ios = 12.1xi
cisco / ios = 12.1xj
cisco / ios = 12.1xm
cisco / ios = 12.1xp
cisco / ios = 12.1xr
cisco / ios = 12.1yb
cisco / ios = 12.1yd
cisco / ios = 12.1yf
cisco / ios = 12.1yi
cisco / ios = 12.2
cisco / ios = 12.2b
cisco / ios = 12.2bw
cisco / ios = 12.2cz
cisco / ios = 12.2dd
cisco / ios = 12.2ex
cisco / ios = 12.2ey
cisco / ios = 12.2fz
cisco / ios = 12.2ira
cisco / ios = 12.2irb
cisco / ios = 12.2irc
cisco / ios = 12.2ixa
cisco / ios = 12.2ixb
cisco / ios = 12.2ixc
cisco / ios = 12.2ixd
cisco / ios = 12.2ixe
cisco / ios = 12.2ixf
cisco / ios = 12.2ixg
cisco / ios = 12.2s
cisco / ios = 12.2sbc
cisco / ios = 12.2se
cisco / ios = 12.2sec
cisco / ios = 12.2sed
cisco / ios = 12.2see
cisco / ios = 12.2sef
cisco / ios = 12.2seg
cisco / ios = 12.2sg
cisco / ios = 12.2sga
cisco / ios = 12.2sq
cisco / ios = 12.2sra
cisco / ios = 12.2srb
cisco / ios = 12.2src
cisco / ios = 12.2su
cisco / ios = 12.2sx
cisco / ios = 12.2sxa
cisco / ios = 12.2sxb
cisco / ios = 12.2sxd
cisco / ios = 12.2sxe
cisco / ios = 12.2sxf
cisco / ios = 12.2sxh
cisco / ios = 12.2sxi
cisco / ios = 12.2t
cisco / ios = 12.2tpc
cisco / ios = 12.2xa
cisco / ios = 12.2xb
cisco / ios = 12.2xd
cisco / ios = 12.2xe
cisco / ios = 12.2xg
cisco / ios = 12.2xj
cisco / ios = 12.2xk
cisco / ios = 12.2xl
cisco / ios = 12.2xm
cisco / ios = 12.2xo
cisco / ios = 12.2xq
cisco / ios = 12.2xt
cisco / ios = 12.2xv
cisco / ios = 12.2xw
cisco / ios = 12.2ya
cisco / ios = 12.2yb
cisco / ios = 12.2yc
cisco / ios = 12.2ye
cisco / ios = 12.2yf
cisco / ios = 12.2yh
cisco / ios = 12.2yl
cisco / ios = 12.2ym
cisco / ios = 12.2yn
cisco / ios = 12.2yq
cisco / ios = 12.2yu
cisco / ios = 12.2yv
cisco / ios = 12.2yx
cisco / ios = 12.2yz
cisco / ios = 12.2zd
cisco / ios = 12.2zh
cisco / ios = 12.2zj
cisco / ios = 12.2zl
cisco / ios = 12.2zy
cisco / ios = 12.2zya
cisco / ios = 12.3
cisco / ios = 12.3b
cisco / ios = 12.3jk
cisco / ios = 12.3t
cisco / ios = 12.3tpc
cisco / ios = 12.3va
cisco / ios = 12.3xa
cisco / ios = 12.3xc
cisco / ios = 12.3xd
cisco / ios = 12.3xe
cisco / ios = 12.3xf
cisco / ios = 12.3xg
cisco / ios = 12.3xk
cisco / ios = 12.3xl
cisco / ios = 12.3xq
cisco / ios = 12.3xr
cisco / ios = 12.3xx
cisco / ios = 12.3ya
cisco / ios = 12.3yd
cisco / ios = 12.3yg
cisco / ios = 12.3yh
cisco / ios = 12.3yi
cisco / ios = 12.3yk
cisco / ios = 12.3ym
cisco / ios = 12.3yt
cisco / ios = 12.3yz
cisco / ios = 12.4
cisco / ios = 12.4mr
cisco / ios = 12.4t
cisco / ios = 12.4xa
cisco / ios = 12.4xd
cisco / ios = 12.4xe
cisco / ios = 12.4xf
cisco / ios = 12.4xj
cisco / ios = 12.4xk
cisco / ios = 12.4xt
cisco / ios = 12.4xv
cisco / ios = 12.4xw
cisco / ios = 12.4xy
cisco / ios = 12.4xz
cisco / ios = 12.4ya
cisco / ios = 12.4yb

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.