How severe is CVE-2015-9551?

CVE-2015-9551 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2015-9551 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-9551?

CVE-2015-9551 primarily affects Totolink A850r-v1 Firmware. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-9551?

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

When was CVE-2015-9551 published?

CVE-2015-9551 was published on 2020-11-24 and last updated on 2026-06-17.

CVE-2015-9551

CVE-2015-9551 is a critical-severity vulnerability in Totolink A850r-v1 Firmware with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 4% (90th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Totolink A850r-v1 Firmware
Published: 2020-11-24
Last modified: 2026-06-17

Description

An issue was discovered on TOTOLINK A850R-V1 through 1.0.1-B20150707.1612 and F1-V2 through 1.1-B20150708.1646 devices. There is Remote Code Execution in the management interface via the formSysCmd sysCmd parameter.

Frequently asked questions

What is CVE-2015-9551?: An issue was discovered on TOTOLINK A850R-V1 through 1.0.1-B20150707.1612 and F1-V2 through 1.1-B20150708.1646 devices. There is Remote Code Execution in the management interface via the formSysCmd sysCmd parameter.
How severe is CVE-2015-9551?: CVE-2015-9551 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2015-9551 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-9551?: CVE-2015-9551 primarily affects Totolink A850r-v1 Firmware. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-9551?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2015-9551 published?: CVE-2015-9551 was published on 2020-11-24 and last updated on 2026-06-17.

References

https://pierrekim.github.io/blog/2015-07-16-backdoor-and-RCE-found-in-8-TOTOLINK-products.html

Affected products (8)

cpe:2.3:o:totolink:a850r-v1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:totolink:f1-v2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:totolink:f2-v1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:totolink:n150rt-v2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:totolink:n151rt-v2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:totolink:n300rh-v2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:totolink:n300rh-v3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:totolink:n300rt-v2_firmware:*:*:*:*:*:*:*:*

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CVE-2015-9550 — High (CVSS 7.5): An issue was discovered on TOTOLINK A850R-V1 through 1.0.1-B20150707.1612 and F1-V2 through 1.1-B20150708.1646 devices.…

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