Encrypted messages contents disclosure in KDE KMail

1) Information disclosure

EUVDB-ID: #VU52766

Risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-31855

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to the way messagelib in KDE KMail deletes attachments of encrypted messages on a remote server (e.g. an IMAP server). A remote attacker can send a victim a specially crafted encrypted message and trick the victim into deleting an attachments from such 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.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

messagelib: 16.03.80 - 21.04.0

kmail: 4.11.5 - 21.04.0

CPE2.3

• cpe:2.3:a:kde_org:messagelib:16.03.80:*:*:*:*:*:*:*
• cpe:2.3:a:kde_org:messagelib:16.03.90:*:*:*:*:*:*:*
• cpe:2.3:a:kde_org:messagelib:16.04.0:*:*:*:*:*:*:*
• cpe:2.3:a:kde_org:kmail:4.11.5:*:*:*:*:*:*:*
• cpe:2.3:a:kde_org:kmail:16.11.80:*:*:*:*:*:*:*
• cpe:2.3:a:kde_org:kmail:16.11.90:*:*:*:*:*:*:*

External links

https://kde.org/info/security/advisory-20210429-1.txt

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.