CVE-2011-2165

Exp

The STARTTLS implementation in WatchGuard XCS 9.0 and 9.1 does not properly restrict I/O buffering, which allows man-in-the-middle attackers to insert commands into encrypted SMTP sessions by sending a cleartext command that is processed after TLS is in place, related to a "plaintext command injection" attack, a similar issue to CVE-2011-0411.

Published: 2011-05-23 Last update: 2026-04-29 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2011-2165 is rated High Exploit Risk (73.6/100): CVSS Medium severity, with high exploitation likelihood (EPSS 6.63%, 91th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2011-2165

EDB-ID Source Kind Published Link
37440 exploit_db edb 2015-06-30 Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2011-2165

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 2026-01-30 7.08% 6.63% -0.45%
2 2025-09-09 7.17% 7.08% -0.09%
3 2025-06-27 — 7.17% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2011-2165

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2011-2165

Affected software / configurations for CVE-2011-2165

Vendor Product Version Raw CPE
watchguard xcs 9.0 cpe:2.3:a:watchguard:xcs:9.0:*:*:*:*:*:*:*
watchguard xcs 9.1 cpe:2.3:a:watchguard:xcs:9.1:*:*:*:*:*:*:*

References for CVE-2011-2165

cvelogic Threat Intelligence