CVE intelligence and bounded remediation
CVE-2023-51747 — Apache James prior to versions 3.8.1 and 3.7.5 is vulnerable to SMTP smuggling
Apache James prior to versions 3.8.1 and 3.7.5 is vulnerable to SMTP smuggling. A lenient behaviour in line delimiter handling might create a difference of interpretation between the sender and the receiver which can be exploited by an attacker to forge an SMTP envelop, allowing for instance to bypass SPF checks. The patch implies enforcement of CRLF as a line delimiter as part of the DATA transaction. We recommend James users to upgrade to non vulnerable versions.
- Severity
- High
- CVSS
- 7.1 (3.1)
- Published
- 2024-02-27
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-20, CWE-290, CWE-444
Affected products
- apache / james / 3.7.5
- apache / james / 3.8.1
Matched remediation archetype
HTTP request smuggling and message-boundary ambiguity
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Check exposure
- Inventory every proxy, CDN, gateway, load balancer, service mesh, and application server hop on affected request paths.
- Compare documented parsing and normalization behavior for message length, transfer coding, duplicate headers, and protocol translation.
- Identify connection reuse and which downstream services trust headers added by intermediaries.
Remediate safely
- Update affected intermediaries and origin servers and align them on a single standards-compliant request framing policy.
- Reject ambiguous length, transfer-coding, duplicate, malformed, and unsupported framing before forwarding.
- Normalize or remove hop-by-hop and identity headers at one controlled boundary and add multi-hop regression tests.
Authoritative sources
Complete CVE record and remediation plan
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