CVE-2009-0077

The firewall engine in Microsoft Forefront Threat Management Gateway, Medium Business Edition (TMG MBE); and Internet Security and Acceleration (ISA) Server 2004 SP3, 2006, 2006 Supportability Update, and 2006 SP1; does not properly manage the session state of web listeners, which allows remote attackers to cause a denial of service (many stale sessions) via crafted packets, aka "Web Proxy TCP State Limited Denial of Service Vulnerability."

Published: 2009-04-15 Last update: 2026-04-23 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2009-0077 is rated Moderate Risk (49.8/100): CVSS Medium severity, with high exploitation likelihood (EPSS 78.50%, 100th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2009-0077

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 88.70% 78.50% -10.21%
2 2026-03-04 83.64% 88.70% +5.07%
3 2026-03-01 — 83.64% —

Full EPSS history (46 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2009-0077

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2009-0077

Affected software / configurations for CVE-2009-0077

Vendor Product Version Raw CPE
microsoft forefront_threat_management_gateway — cpe:2.3:a:microsoft:forefront_threat_management_gateway:-:-:medium_business:*:*:*:*:*
microsoft internet_security_and_acceleration_server 2004 cpe:2.3:a:microsoft:internet_security_and_acceleration_server:2004:sp3:enterprise:*:*:*:*:*
microsoft internet_security_and_acceleration_server 2004 cpe:2.3:a:microsoft:internet_security_and_acceleration_server:2004:sp3:standard:*:*:*:*:*
microsoft internet_security_and_acceleration_server 2006 cpe:2.3:a:microsoft:internet_security_and_acceleration_server:2006:sp1:*:*:*:*:*:*
microsoft internet_security_and_acceleration_server 2006 cpe:2.3:a:microsoft:internet_security_and_acceleration_server:2006:supportability:*:*:*:*:*:*

References for CVE-2009-0077

cvelogic Threat Intelligence