CVE-2021-27504 | Texas Instruments FREERTOS Integer Overflow or Wraparound

Texas Instruments devices running FREERTOS, malloc returns a valid pointer to a small buffer on extremely large values, which can trigger an integer overflow vulnerability in 'malloc' for FreeRTOS, resulting in code execution.

Published: 2023-11-21 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-27504 is rated Moderate Risk (41/100): CVSS High severity, with low exploitation likelihood (EPSS 0.12%). Review affected assets and schedule remediation.

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-2021-27504

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 2025-11-21 0.05% 0.12% +0.08%
2 2025-11-18 0.07% 0.05% -0.02%
3 2025-03-30 — 0.07% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-27504

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.4 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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: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.
 1.4 5.9 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:L)
A normal user session is enough; they don’t have to be admin.
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.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2021-27504

Affected software / configurations for CVE-2021-27504

Vendor Product Version Raw CPE
amazon freertos 10.4.1 cpe:2.3:o:amazon:freertos:10.4.1:*:*:*:*:*:*:*
ti simplelink_cc13xx_software_development_kit < 4.40.00 cpe:2.3:a:ti:simplelink_cc13xx_software_development_kit:*:*:*:*:*:*:*:*
ti simplelink_cc26xx_software_development_kit < 4.40.00 cpe:2.3:a:ti:simplelink_cc26xx_software_development_kit:*:*:*:*:*:*:*:*
ti simplelink_cc32xx_software_development_kit < 4.10.03 cpe:2.3:a:ti:simplelink_cc32xx_software_development_kit:*:*:*:*:*:*:*:*
ti simplelink_msp432e401y — cpe:2.3:a:ti:simplelink_msp432e401y:-:*:*:*:*:*:*:*
ti simplelink_msp432e411y — cpe:2.3:a:ti:simplelink_msp432e411y:-:*:*:*:*:*:*:*

References for CVE-2021-27504

cvelogic Threat Intelligence