Detections
Analytics

Linux Distros Unpatched Vulnerability : CVE-2021-31855

medium Nessus Plugin ID 258320

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Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

 - KDE Messagelib through 5.17.0 reveals cleartext of encrypted messages in some situations. Deleting an attachment of a decrypted encrypted message stored on a remote server (e.g., an IMAP server) causes KMail to upload the decrypted content of the message to the remote server. With a crafted message, a user could be tricked into decrypting an encrypted message and then deleting an attachment attached to this message.
 If the attacker has access to the messages stored on the email server, then the attacker could read the decrypted content of the encrypted message. This occurs in ViewerPrivate::deleteAttachment in messageviewer/src/viewer/viewer_p.cpp. (CVE-2021-31855)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://ubuntu.com/security/CVE-2021-31855

Plugin Details

Severity: Medium

ID: 258320

File Name: unpatched_CVE_2021_31855.nasl

Version: 1.1

Type: local

Agent: unix

Family: Misc.

Published: 8/30/2025

Updated: 8/30/2025

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Medium

Base Score: 4

Temporal Score: 3

Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:N/A:N

CVSS Score Source: CVE-2021-31855

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:kf5-messagelib, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:kdepim4, cpe:/o:canonical:ubuntu_linux:20.04:-:lts

Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 6/2/2021

Reference Information

CVE: CVE-2021-31855