CVE-2023-51518: Apache James server: Privilege escalation via JMX pre-authentication deserialization

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 1.2%, percentile 68: FIRST’s model estimates a 1.2% chance of exploitation activity in the next 30 days, higher than 68% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes org.apache.james:james-server (Maven) <= 3.7.4, fixed in 3.7.5; org.apache.james:james-server (Maven) >= 3.8.0, < 3.8.1, fixed in 3.8.1. Check your lockfile, including transitive dependencies.

What it is

Apache James prior to version 3.7.5 and 3.8.0 exposes a JMX endpoint on localhost subject to pre-authentication deserialisation of untrusted data. Given a deserialisation gadjet, this could be leveraged as part of an exploit chain that could result in privilege escalation. Note that by default JMX endpoint is only bound locally. We recommend users to: - Upgrade to a non-vulnerable Apache James version - Run Apache James isolated from other processes (docker - dedicated virtual machine) - If possible turn off JMX

From the GitHub advisory

Apache James prior to version 3.7.5 and 3.8.0 exposes a JMX endpoint on localhost subject to pre-authentication deserialisation of untrusted data. Given a deserialisation gadjet, this could be leveraged as part of an exploit chain that could result in privilege escalation. Note that by default JMX endpoint is only bound locally.

We recommend users to: - Upgrade to a non-vulnerable Apache James version

- Run Apache James isolated from other processes (docker - dedicated virtual machine) - If possible turn off JMX

Weakness type: CWE-502.

Product: org.apache.james:james-server (Maven) · Assigned by: apache · Published: 2024-02-27

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 1.19% probability of exploitation activity in the next 30 days; percentile 68.

Timeline

• 2024-02-27 — CVE record published by apache
• 2024-02-27 — GitHub-reviewed advisory GHSA-px7w-c9gw-7gj3 published (critical)
• 2024-08-22 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. lists.apache.org lists.apache.org

Vulnerability records

1. GitHub Advisory GHSA-px7w-c9gw-7gj3 github.com
2. CVE.org record CVE-2023-51518 cve.org
3. NVD entry CVE-2023-51518 nvd.nist.gov

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