CVE-2021-3693 [High] | XSS in Ledgersmb

LedgerSMB does not check the origin of HTML fragments merged into the browser's DOM. By sending a specially crafted URL to an authenticated user, this flaw can be abused for remote code execution and information disclosure.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-12-13	1.76%	0.79%	-0.97%
2	2025-11-21	1.54%	1.76%	+0.22%
3	2025-11-18	—	1.54%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-12-13

1.76%

0.79%

-0.97%

2025-11-21

1.54%

1.76%

+0.22%

2025-11-18

—

1.54%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
8.8	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. 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.	2.8	5.9	[email protected]
9.6	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. 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:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. 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.	2.8	6.0	[email protected]
6.8	2.0	MEDIUM	`AV:N/AC:M/Au:N/C:P/I:P/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. 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.	8.6	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

8.8

3.1

HIGH

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

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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.

2.8

5.9

[email protected]

9.6

3.1

CRITICAL

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

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
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.

2.8

6.0

[email protected]

6.8

2.0

MEDIUM

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

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
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.

8.6

6.4

[email protected]

OS Trackers for CVE-2021-3693

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2021-3693 not yet assigned priority: Debian including 1 source packages (ledgersmb), 2 status rows across 2 suites (bookworm, bullseye): resolved 2.	https://security-tracker.debian.org/tracker/CVE-2021-3693
`ubuntu`	medium	CVE-2021-3693 medium priority: Ubuntu including 1 source packages (ledgersmb), 14 status rows across 14 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, trusty, upstream, xenial): released 8, ignored 5, DNE 1.	https://ubuntu.com/security/CVE-2021-3693

Affected software / configurations for CVE-2021-3693

Vendor	Product	Version	Raw CPE
ledgersmb	ledgersmb	>= 1.5.0, <= 1.5.30	cpe:2.3:a:ledgersmb:ledgersmb::::::::
ledgersmb	ledgersmb	>= 1.6.0, <= 1.6.33	cpe:2.3:a:ledgersmb:ledgersmb::::::::
ledgersmb	ledgersmb	>= 1.7.0, <= 1.7.32	cpe:2.3:a:ledgersmb:ledgersmb::::::::
ledgersmb	ledgersmb	>= 1.8.0, <= 1.8.17	cpe:2.3:a:ledgersmb:ledgersmb::::::::
debian	debian_linux	10.0	cpe:2.3:o:debian:debian_linux:10.0:::::::*
debian	debian_linux	11.0	cpe:2.3:o:debian:debian_linux:11.0:::::::*

References for CVE-2021-3693

URL	Tags
https://huntr.dev/bounties/daf1384d-648a-43fd-9b35-5c37d8ead667	Third Party Advisory
https://ledgersmb.org/cve-2021-3693-cross-site-scripting	Patch Vendor Advisory
https://www.debian.org/security/2021/dsa-4962	Third Party Advisory

URL

CVE-2021-3693 | Cross-site Scripting (XSS) - DOM in ledgersmb/ledgersmb

Exploit prediction scoring system (EPSS) score for CVE-2021-3693

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3693

Weakness enumeration for CVE-2021-3693

OS Trackers for CVE-2021-3693

Affected software / configurations for CVE-2021-3693

References for CVE-2021-3693