CVE-2021-38448 [High] | Code Injection in Symbio 700

CVE-2021-38448 is rated Moderate Risk (41.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.13%). Review affected assets and schedule remediation.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-05-11	0.15%	0.13%	-0.02%
2	2025-03-19	0.10%	0.15%	+0.05%
3	2024-12-17	—	0.10%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-05-11

0.15%

0.13%

-0.02%

2025-03-19

0.10%

0.15%

+0.05%

2024-12-17

—

0.10%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.5	3.1	HIGH	`CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H` Click to expand Attack vector (AV:P) Hands-on access—USB, keyboard, opening the case—not something you do purely over the wire. 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:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. 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.	0.9	6.0	[email protected]
7.6	3.1	HIGH	`CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H` Click to expand Attack vector (AV:P) Hands-on access—USB, keyboard, opening the case—not something you do purely over the wire. 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:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. 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.	0.9	6.0	[email protected]
4.6	2.0	MEDIUM	`AV:L/AC:L/Au:N/C:P/I:P/A:P` Click to expand Access vector (AV:L) Requires local access to the target system. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	3.9	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.5

3.1

HIGH

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H Click to expand

Attack vector (AV:P): Hands-on access—USB, keyboard, opening the case—not something you do purely over the wire.
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:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
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.

0.9

6.0

[email protected]

7.6

3.1

HIGH

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H Click to expand

Attack vector (AV:P): Hands-on access—USB, keyboard, opening the case—not something you do purely over the wire.
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:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
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.

0.9

6.0

[email protected]

4.6

2.0

MEDIUM

AV:L/AC:L/Au:N/C:P/I:P/A:P Click to expand

Access vector (AV:L): Requires local access to the target system.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

3.9

6.4

[email protected]

Affected software / configurations for CVE-2021-38448

Vendor	Product	Version	Raw CPE
trane	symbio_700	< 1.00.0023	cpe:2.3:a:trane:symbio_700::::::::
trane	symbio_800	< 1.30.0008	cpe:2.3:a:trane:symbio_800::::::::
trane	symbio_800	< 1.10.0010	cpe:2.3:a:trane:symbio_800::::::::

References for CVE-2021-38448

URL	Tags
https://us-cert.cisa.gov/ics/advisories/icsa-21-266-01	Mitigation Third Party Advisory US Government Resource

URL

CVE-2021-38448 | Trane Symbio Improper Control of Generation of Code

Exploit prediction scoring system (EPSS) score for CVE-2021-38448

Common vulnerability scoring system (CVSS) metrics for CVE-2021-38448

Weakness enumeration for CVE-2021-38448

Affected software / configurations for CVE-2021-38448

References for CVE-2021-38448