CVE-2021-38542 | Apache James vulnerable to STARTTLS command injection (IMAP and POP3)

Apache James prior to release 3.6.1 is vulnerable to a buffering attack relying on the use of the STARTTLS command. This can result in Man-in -the-middle command injection attacks, leading potentially to leakage of sensible information.

Published: 2022-01-04 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-38542 is rated Moderate Risk (53.8/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.35%). Core evidence: EPSS rose +1.73% over the last day, indicating growing attacker interest. Mandatory action: 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-2021-38542

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 0.61% 2.35% +1.73%
2 2025-09-14 0.84% 0.61% -0.23%
3 2025-09-09 0.84%

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-38542

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-38542

GitHub Security Advisory for CVE-2021-38542

GHSA-84wg-rgp8-2hg4 · Severity: medium · Ecosystem: maven — Command Injection in Apache James

Affected software / configurations for CVE-2021-38542

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

References for CVE-2021-38542

URL Tags
http://www.openwall.com/lists/oss-security/2022/01/04/1 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2022/09/20/1 Mailing List Third Party Advisory
https://www.openwall.com/lists/oss-security/2022/01/04/1 Mailing List Third Party Advisory
cvelogic Threat Intelligence