How severe is CVE-2021-33726?

CVE-2021-33726 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-33726 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33726?

CVE-2021-33726 primarily affects Siemens Sinec Nms. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-33726?

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-2021-33726 published?

CVE-2021-33726 was published on 2021-10-12 and last updated on 2026-06-17.

CVE-2021-33726

CVE-2021-33726 is a high-severity vulnerability in Siemens Sinec Nms with a CVSS 3.x base score of 7.5. 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-22.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (64th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-22
Affected product: Siemens Sinec Nms
Published: 2021-10-12
Last modified: 2026-06-17

Description

A vulnerability has been identified in SINEC NMS (All versions < V1.0 SP2 Update 1). The affected system allows to download arbitrary files under a user controlled path and does not correctly check if the relative path is still within the intended target directory.

Frequently asked questions

What is CVE-2021-33726?: A vulnerability has been identified in SINEC NMS (All versions < V1.0 SP2 Update 1). The affected system allows to download arbitrary files under a user controlled path and does not correctly check if the relative path is still within the intended target directory.
How severe is CVE-2021-33726?: CVE-2021-33726 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-33726 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33726?: CVE-2021-33726 primarily affects Siemens Sinec Nms. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-33726?: 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-2021-33726 published?: CVE-2021-33726 was published on 2021-10-12 and last updated on 2026-06-17.

References

https://cert-portal.siemens.com/productcert/pdf/ssa-163251.pdf

Affected products (4)

cpe:2.3:a:siemens:sinec_nms:*:*:*:*:*:*:*:*
cpe:2.3:a:siemens:sinec_nms:1.0:-:*:*:*:*:*:*
cpe:2.3:a:siemens:sinec_nms:1.0:sp1:*:*:*:*:*:*
cpe:2.3:a:siemens:sinec_nms:1.0:sp2:*:*:*:*:*:*

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