CVE-2021-28091 [High] | Security Vulnerability in Lasso

CVE-2021-28091 is rated Moderate Risk (54.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.64%). Review affected assets and schedule remediation.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-05-13	0.51%	0.64%	+0.13%
2	2025-12-28	0.43%	0.51%	+0.08%
3	2025-12-27	—	0.43%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-05-13

0.51%

0.64%

+0.13%

2025-12-28

0.43%

0.51%

+0.08%

2025-12-27

—

0.43%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.5	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N` 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: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:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:N) Service keeps running; no real outage angle.	3.9	3.6	[email protected]
5.0	2.0	MEDIUM	`AV:N/AC:L/Au:N/C:N/I:P/A:N` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:N) No availability impact.	10.0	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.5

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N 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: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:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N): Service keeps running; no real outage angle.

3.9

3.6

[email protected]

5.0

2.0

MEDIUM

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

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:N): No availability impact.

10.0

2.9

[email protected]

OS Trackers for CVE-2021-28091

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2021-28091 not yet assigned priority: Debian including 1 source packages (lasso), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2021-28091
`redhat`	high	—	https://access.redhat.com/security/cve/CVE-2021-28091
`suse`	high	CVE-2021-28091 severity important: SUSE including 18 source package names (lasso-2.5.1-8.el7_9, lasso-2.6.0-12.el8, …), 23 product×package rows across 11 product lines (SUSE Liberty Linux 7, SUSE Liberty Linux 7 LTSS, … (11 product lines)): Fixed 23.	https://www.suse.com/security/cve/CVE-2021-28091/
`ubuntu`	medium	CVE-2021-28091 medium priority: Ubuntu including 1 source packages (lasso), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 9, released 4, DNE 1, needed 1, needs-triage 1.	https://ubuntu.com/security/CVE-2021-28091

Affected software / configurations for CVE-2021-28091

Vendor	Product	Version	Raw CPE
entrouvert	lasso	< 2.7.0	cpe:2.3:a:entrouvert:lasso::::::::
debian	debian_linux	9.0	cpe:2.3:o:debian:debian_linux:9.0:::::::*
debian	debian_linux	10.0	cpe:2.3:o:debian:debian_linux:10.0:::::::*
fedoraproject	fedora	33	cpe:2.3:o:fedoraproject:fedora:33:::::::*
fedoraproject	fedora	34	cpe:2.3:o:fedoraproject:fedora:34:::::::*

References for CVE-2021-28091

URL	Tags
http://listes.entrouvert.com/arc/lasso/	Product
https://git.entrouvert.org/lasso.git/commit/?id=076a37d7f0eb74001127481da2d355683693cde9	Patch Vendor Advisory
https://git.entrouvert.org/lasso.git/tree/NEWS?id=v2.7.0	Release Notes Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00013.html	Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SI4YAQF4VEV2KHQ6OXXZL7CJK7IZQ3EG/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YSVWOHBBWLI2RB5C6TXINFEJRT4YSD3D/
https://www.debian.org/security/2021/dsa-4926	Third Party Advisory

URL

CVE-2021-28091

Exploit prediction scoring system (EPSS) score for CVE-2021-28091

Common vulnerability scoring system (CVSS) metrics for CVE-2021-28091

Weakness enumeration for CVE-2021-28091

OS Trackers for CVE-2021-28091

Affected software / configurations for CVE-2021-28091

References for CVE-2021-28091