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CVE-2021-31988

27
FAUCET Score

CVE-2021-31988 is a critical vulnerability affecting Axis OS, Axis OS 2016, Axis OS 2018, and Axis OS 2020, where improper validation of a user-controlled parameter in SMTP test functionality allows for the injection of arbitrary SMTP headers via CRLF characters. This flaw carries a high CVSS score of 8.8, indicating a network-based attack with low complexity, requiring user interaction, and potentially leading to high impact on confidentiality, integrity, and availability. While there is no evidence of active exploitation or public exploit code (Metasploit, Nuclei, ExploitDB), the vulnerability has garnered significant community discussion and media coverage, including articles detailing its potential for remote code execution and data theft.

Impacted Technologies

VendorProductVersion(s)CPE
< 10.7CPE matchmatch criteria
cpe:2.3:o:axis:axis_os:*:*:*:*:active:*:*:*
< 6.50.5.5CPE matchmatch criteria
cpe:2.3:o:axis:axis_os_2016:*:*:*:*:lts:*:*:*
< 8.40.4.3CPE matchmatch criteria
cpe:2.3:o:axis:axis_os_2018:*:*:*:*:lts:*:*:*
< 9.80.3.5CPE matchmatch criteria
cpe:2.3:o:axis:axis_os_2020:*:*:*:*:lts:*:*:*

CVSS Data

CVSS version used by this source: 3.1

8.8HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
2.8
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.92%
Probability of exploitation in next 30 days
EPSS Percentile
56.7%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0092 is in the 58th percentile among its peer group of 14,875 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.2 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.1 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

axis.com / files/tech_notes/CVE-2021-31988.pdf
Vendor Advisory