How severe is CVE-2021-34581?

CVE-2021-34581 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 none, integrity none, and availability high.

Is CVE-2021-34581 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-34581?

CVE-2021-34581 primarily affects Wago 750-880/040-000 Firmware. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-34581?

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-2021-34581 published?

CVE-2021-34581 was published on 2021-08-31 and last updated on 2026-06-17.

CVE-2021-34581

CVE-2021-34581 is a high-severity vulnerability in Wago 750-880/040-000 Firmware 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-772.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.8
EPSS exploit prediction: 1% (59th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-772
Affected product: Wago 750-880/040-000 Firmware
Published: 2021-08-31
Last modified: 2026-06-17

Description

Missing Release of Resource after Effective Lifetime vulnerability in OpenSSL implementation of WAGO 750-831/xxx-xxx, 750-880/xxx-xxx, 750-881, 750-889 in versions FW4 up to FW15 allows an unauthenticated attacker to cause DoS on the device.

Frequently asked questions

What is CVE-2021-34581?: Missing Release of Resource after Effective Lifetime vulnerability in OpenSSL implementation of WAGO 750-831/xxx-xxx, 750-880/xxx-xxx, 750-881, 750-889 in versions FW4 up to FW15 allows an unauthenticated attacker to cause DoS on the device.
How severe is CVE-2021-34581?: CVE-2021-34581 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 none, integrity none, and availability high.
Is CVE-2021-34581 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34581?: CVE-2021-34581 primarily affects Wago 750-880/040-000 Firmware. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-34581?: 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-2021-34581 published?: CVE-2021-34581 was published on 2021-08-31 and last updated on 2026-06-17.

References

https://cert.vde.com/en-us/advisories/vde-2021-038

Affected products (9)

cpe:2.3:o:wago:750-880\/040-000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-880\/025-002_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-880\/025-001_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-880\/025-000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-831\/000-002_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-889_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-881_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-831_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:wago:750-880_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Wago 750-880/040-000 Firmware

CVE-2023-1620 — Medium (CVSS 4.9): Multiple WAGO devices in multiple versions may allow an authenticated remote attacker with high privileges to DoS the…
CVE-2023-1619 — Medium (CVSS 4.9): Multiple WAGO devices in multiple versions may allow an authenticated remote attacker with high privileges to DoS the…

All CVEs affecting Wago 750-880/040-000 Firmware →

Other CWE-772 vulnerabilities

CVE-2020-12134 — Critical (CVSS 9.8): Nanometrics Centaur through 4.3.23 and TitanSMA through 4.2.20 mishandle access control for the syslog log.
CVE-2017-15032 — Critical (CVSS 9.8): ImageMagick version 7.0.7-2 contains a memory leak in ReadYCBCRImage in coders/ycbcr.c.
CVE-2017-14138 — Critical (CVSS 9.8): ImageMagick 7.0.6-5 has a memory leak vulnerability in ReadWEBPImage in coders/webp.c because memory is not freed in…
CVE-2017-11641 — Critical (CVSS 9.8): GraphicsMagick 1.3.26 has a Memory Leak in the PersistCache function in magick/pixel_cache.c during writing of Magick…
CVE-2020-14339 — High (CVSS 8.8): A flaw was found in libvirt, where it leaked a file descriptor for `/dev/mapper/control` into the QEMU process. This…
CVE-2018-19760 — High (CVSS 8.8): cfg_init in confuse.c in libConfuse 3.2.2 has a memory leak.

Browse all CWE-772 vulnerabilities →