CVE-2020-15953 Other in n/a

What is CVE-2020-15953?

CVE-2020-15953 is a high-severity vulnerability in Debian Debian Linux, published on 27 Jul 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

LibEtPan through 1.9.4, as used in MailCore 2 through 0.6.3 and other products, has a STARTTLS buffering issue that affects IMAP, SMTP, and POP3. When a server sends a "begin TLS" response, the client reads additional data (e.g., from a meddler-in-the-middle attacker) and evaluates it in a TLS context, aka "response injection."

Weakness: CWE-74

Which versions are affected by CVE-2020-15953?

It affects 4 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Libetpan Project Libetpan, Libmailcore Mailcore2.

How do I fix CVE-2020-15953?

Upgrade to a fixed version.

Is CVE-2020-15953 being exploited?

There is no known exploitation of CVE-2020-15953 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2020-15953, DLA-2329-1, GHSA-f329-rp43-94r4, MGASA-2020-0366, UBUNTU-CVE-2020-15953, USN-4598-1 and 2 more.