CVE-2023-21406 | Heap-based buffer overflow in Axis A1001 Network Door Controller's OSDP communication

Ariel Harush and Roy Hodir from OTORIO have found a flaw in the AXIS A1001 when communicating over OSDP. A heap-based buffer overflow was found in the pacsiod process which is handling the OSDP communication allowing to write outside of the allocated buffer. By appending invalid data to an OSDP message it was possible to write data beyond the heap allocated buffer. The data written outside the buffer could be used to execute arbitrary code.  lease refer to the Axis security advisory for more information, mitigation and affected products and software versions.

Published: 2023-07-25 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-21406 is rated Low Risk (35.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.28%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-21406

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.06% 0.28% +0.22%
2 2023-07-25 0.06%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-21406

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 3.1 HIGH
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.6 5.5 [email protected]
8.8 3.1 HIGH
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]

Weakness enumeration for CVE-2023-21406

Affected software / configurations for CVE-2023-21406

Vendor Product Version Raw CPE
axis a1001_firmware <= 1.65.4 cpe:2.3:o:axis:a1001_firmware:*:*:*:*:*:*:*:*

References for CVE-2023-21406

cvelogic Threat Intelligence