CVE-2021-31988

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-10-05 · updated 2026-06-17
Weakness: CWE-1286

Description

A user controlled parameter related to SMTP test functionality is not correctly validated making it possible to add the Carriage Return and Line Feed (CRLF) control characters and include arbitrary SMTP headers in the generated test email.

Affected products

Axis Communications AB AXIS OS: before 10.7 — fixed in 10.7
Axis Os 2016: before 6.50.5.5 — fixed in 6.50.5.5
Axis Os 2018: before 8.40.4.3 — fixed in 8.40.4.3
Axis Os 2020: before 9.80.3.5 — fixed in 9.80.3.5

How to fix

Upgrade to a fixed version: Axis Communications AB AXIS OS 10.7; Axis Os 2016 6.50.5.5; Axis Os 2018 8.40.4.3; Axis Os 2020 9.80.3.5. Check the vendor advisory for mitigations.

References

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