How severe is CVE-2011-4877?

CVE-2011-4877 has a CVSS 2.0 base score of 7.1, rated high severity.

Is CVE-2011-4877 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 8% (94th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2011-4877?

CVE-2011-4877 primarily affects Siemens Wincc Flexible. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2011-4877?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2011-4877 published?

CVE-2011-4877 was published on 2012-02-03 and last updated on 2026-06-16.

CVE-2011-4877

CVE-2011-4877 is a high-severity vulnerability in Siemens Wincc Flexible with a CVSS 2.0 base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 2.0 base score 7.1)
EPSS exploit prediction: 8% (94th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Siemens Wincc Flexible
Published: 2012-02-03
Last modified: 2026-06-16

Description

HmiLoad in the runtime loader in Siemens WinCC flexible 2004, 2005, 2007, and 2008; WinCC V11 (aka TIA portal); the TP, OP, MP, Comfort Panels, and Mobile Panels SIMATIC HMI panels; WinCC V11 Runtime Advanced; and WinCC flexible Runtime, when Transfer Mode is enabled, allows remote attackers to cause a denial of service (application crash) by sending crafted data over TCP.

Frequently asked questions

What is CVE-2011-4877?: HmiLoad in the runtime loader in Siemens WinCC flexible 2004, 2005, 2007, and 2008; WinCC V11 (aka TIA portal); the TP, OP, MP, Comfort Panels, and Mobile Panels SIMATIC HMI panels; WinCC V11 Runtime Advanced; and WinCC flexible Runtime, when Transfer Mode is enabled, allows remote attackers to cause a denial of service (application crash) by sending crafted data over TCP.
How severe is CVE-2011-4877?: CVE-2011-4877 has a CVSS 2.0 base score of 7.1, rated high severity.
Is CVE-2011-4877 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 8% (94th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2011-4877?: CVE-2011-4877 primarily affects Siemens Wincc Flexible. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2011-4877?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2011-4877 published?: CVE-2011-4877 was published on 2012-02-03 and last updated on 2026-06-16.

References

Affected products (12)

cpe:2.3:a:siemens:wincc_flexible:2004:*:*:*:*:*:*:*
cpe:2.3:a:siemens:wincc_flexible:2005:*:*:*:*:*:*:*
cpe:2.3:a:siemens:wincc_flexible:2007:*:*:*:*:*:*:*
cpe:2.3:a:siemens:wincc_flexible:2008:*:*:*:*:*:*:*
cpe:2.3:a:siemens:wincc:v11:*:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_hmi_panels:comfort_panels:*:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_hmi_panels:mobile_panels:*:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_hmi_panels:mp:*:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_hmi_panels:op:*:*:*:*:*:*:*
cpe:2.3:a:siemens:simatic_hmi_panels:tp:*:*:*:*:*:*:*
cpe:2.3:a:siemens:wincc_runtime_advanced:v11:*:*:*:*:*:*:*
cpe:2.3:a:siemens:wincc_flexible_runtime:*:*:*:*:*:*:*:*

More vulnerabilities in Siemens Wincc Flexible

CVE-2011-4514 — Critical (CVSS 10.0): The TELNET daemon in Siemens WinCC flexible 2004, 2005, 2007, and 2008; WinCC V11 (aka TIA portal); the TP, OP, MP,…
CVE-2011-4513 — Critical (CVSS 10.0): Siemens WinCC flexible 2004, 2005, 2007, and 2008; WinCC V11 (aka TIA portal); the TP, OP, MP, Comfort Panels, and…
CVE-2011-4509 — Critical (CVSS 10.0): The HMI web server in Siemens WinCC flexible 2004, 2005, 2007, and 2008; WinCC V11 (aka TIA portal); the TP, OP, MP,…
CVE-2011-4876 — Critical (CVSS 9.3): Directory traversal vulnerability in HmiLoad in the runtime loader in Siemens WinCC flexible 2004, 2005, 2007, and…
CVE-2011-4875 — Critical (CVSS 9.3): Stack-based buffer overflow in HmiLoad in the runtime loader in Siemens WinCC flexible 2004, 2005, 2007, and 2008;…
CVE-2011-4508 — Critical (CVSS 9.3): The HMI web server in Siemens WinCC flexible 2004, 2005, 2007, and 2008 before SP3; WinCC V11 (aka TIA portal) before…

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