Skip to main content
Mallory
MediumPublic exploit

Apache Log4j Core Socket Appender TLS Hostname Verification Bypass

IdentifiersCVE-2025-68161CWE-297· Improper Validation of Certificate…

CVE-2025-68161 affects Apache Log4j Core Socket Appender in versions 2.0-beta9 through 2.25.2. The Socket Appender fails to perform TLS hostname verification of the peer certificate even when hostname verification is explicitly enabled via the verifyHostName configuration attribute or the log4j2.sslVerifyHostName system property. As a result, the appender may accept a certificate that chains to a trusted certification authority without verifying that the certificate identity matches the intended remote log receiver. This is a transport security validation flaw that can enable interception or redirection of log traffic in man-in-the-middle conditions.

Share:
For your environment

Are you exposed to this one?

Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.

ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

A successful attacker-in-the-middle can intercept, observe, and potentially redirect log traffic sent over TLS by the vulnerable Socket Appender. Depending on what the application logs, this may expose sensitive operational, security, authentication, or application data contained in log streams. It may also undermine integrity of centralized logging by allowing logs to be delivered to an attacker-controlled endpoint rather than the legitimate receiver.

Mitigation

If you can’t patch tonight, do this now.

If immediate upgrade is not possible, configure the Socket Appender to use a private or otherwise restricted trust root so that only certificates issued by a narrowly controlled CA are trusted. This reduces the set of certificates an attacker could use successfully. Additional exposure reduction depends on preventing interception or redirection of traffic between the client and the log receiver.

Remediation

Patch, then assume compromise.

Upgrade Apache Log4j Core to version 2.25.3 or later, which addresses this issue. If the affected component is bundled in another product, apply the vendor-provided update that incorporates the fixed Log4j Core release.
PUBLIC EXPLOITS

Exploits

No valid public exploits. Mallory filtered out 1 candidate as fakes, detection scripts, or README-only repos.

VALID 0 / 1 TOTALView more in app

All candidate exploits were filtered out by Mallory's validation.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Apache Software FoundationLog4japplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity27

Community discussion across Reddit, Mastodon, and other social sources.