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Fencer Intel
high 7.5

CVE-2021-28091 json

Lasso all versions prior to 2.7.0 has improper verification of a cryptographic signature.

published 5y ago modified 4mo ago also EUVD-2021-14796

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 72%
public exploits
0
none known

Summary

Lasso all versions prior to 2.7.0 has improper verification of a cryptographic signature.

Patch / fix

  • entrouvert lasso 2.7.0
  • lasso Debian 14, Debian 13, Debian 12 2.6.1-3

debian advisories DEBIAN-CVE-2021-28091

  • lasso Ubuntu 18.04 LTS 2.5.1-0ubuntu1.2
  • lasso Ubuntu 20.04 LTS 2.6.0-7ubuntu1.2

ubuntu advisories UBUNTU-CVE-2021-28091

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • lasso RHEL 8 2.6.0-12.el8
  • lasso RHEL 7 2.5.1-8.el7_9
  • lasso-python RHEL 7 2.5.1-8.el7_9

red hat advisories RHSA-2021:4325RHSA-2021:2989

  • lasso SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 2.6.1-8.7.2

suse advisories SUSE-SU-2021:2589-1

  • lasso openSUSE Tumbleweed 2.7.0-2.2
  • lasso openSUSE Leap 15.2 2.6.1-lp152.2.3.1

opensuse advisories openSUSE-SU-2024:10909-1openSUSE-SU-2021:1057-1

  • lasso AlmaLinux 8 2.6.0-12.el8

almalinux advisories ALSA-2021:4325

  • lasso Rocky Linux 8 2.6.0-12.el8

rocky linux advisories RLSA-2021:4325

  • lasso CBL-Mariner 2.0 2.8.0-1

azure linux advisories AZL-7255

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Is CVE-2021-28091 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-28091 updated cvss 8.8

lasso: XML signature wrapping vulnerability when parsing SAML responses

  • Red Hat Enterprise Linux 6 lasso, lasso-python
    affected: no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder (v. 8) lasso-devel 2.6.0-12.el8, lasso-debuginfo 2.6.0-12.el8, lasso-debugsource 2.6.0-12.el8, java-lasso-debuginfo 2.6.0-12.el8, perl-lasso-debuginfo 2.6.0-12.el8, python3-lasso-debuginfo 2.6.0-12.el8 Red Hat Enterprise Linux AppStream (v. 8) lasso 2.6.0-12.el8
    fixed: vendor fix RHSA-2021:4325
  • Red Hat Enterprise Linux Server (v. 7) lasso 2.5.1-8.el7_9, lasso-python 2.5.1-8.el7_9 Red Hat Enterprise Linux Server Optional (v. 7) lasso-devel 2.5.1-8.el7_9, lasso-debuginfo 2.5.1-8.el7_9 Red Hat Enterprise Linux Workstation (v. 7) lasso 2.5.1-8.el7_9 Red Hat Enterprise Linux Workstation Optional (v. 7) lasso-python 2.5.1-8.el7_9
    fixed: vendor fix RHSA-2021:2989
  • Red Hat Enterprise Linux 9 lasso, python3-lasso
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.38% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.