CVE-2021-40111 | Apache James IMAP parsing Denial Of Service

In Apache James, while fuzzing with Jazzer the IMAP parsing stack, we discover that crafted APPEND and STATUS IMAP command could be used to trigger infinite loops resulting in expensive CPU computations and OutOfMemory exceptions. This can be used for a Denial Of Service attack. The IMAP user needs to be authenticated to exploit this vulnerability. This affected Apache James prior to version 3.6.1. This vulnerability had been patched in Apache James 3.6.1 and higher. We recommend the upgrade.

Published: 2022-01-04 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-40111 is rated Moderate Risk (54.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.12%). EPSS rose +1.14% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-40111

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.99% 2.12% +1.14%
2 2026-05-28 0.73% 0.99% +0.25%
3 2026-03-06 — 0.73% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-40111

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H 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:L)
A normal user session is enough; they don’t have to be admin.
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:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/C:N/I:N/A:P 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:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.0 2.9 [email protected]

Weakness enumeration for CVE-2021-40111

GitHub Security Advisory for CVE-2021-40111

GHSA-fqgw-6qj5-8hmp · Severity: medium · Ecosystem: maven — Infinite Loop in Apache James

Affected software / configurations for CVE-2021-40111

Vendor Product Version Raw CPE
apache james < 3.6.1 cpe:2.3:a:apache:james:*:*:*:*:*:*:*:*

References for CVE-2021-40111

URL Tags
http://www.openwall.com/lists/oss-security/2022/01/04/3 Mailing List Third Party Advisory
https://www.openwall.com/lists/oss-security/2022/01/04/3 Mailing List Third Party Advisory
cvelogic Threat Intelligence