high CVSS 7.8 EPSS <0.1%

CVE-2023-52591·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: reiserfs: Avoid touching renamed directory if parent does not change The VFS will not be locking moved directory if its parent does not change. Change reiserfs rename code to avoid touching renamed directory if its parent does not change as without locking that can corrupt the filesystem.

Severity
high
Software
Kernel
Fixed in
6.7.4
Published

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at <0.1% — higher than 4% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Read the two together. CVE-2023-52591 scores 7.8 on CVSS, so a successful attack would be serious — but at <0.1%, almost nobody is currently attempting it. That is a different situation from a flaw under mass exploitation, and it is usually the difference between patching on your next maintenance window and patching tonight.

Affected versions

From: 6.7

Until: 6.7.4

Fixed in: 6.7.4

How to fix this CVE

Update your Linux kernel to version 6.7.4 or later to resolve a critical filesystem corruption vulnerability in reiserfs rename operations. Systems using reiserfs filesystems are at elevated risk when directory rename operations occur without proper VFS locking. Apply the kernel update immediately and reboot your system to complete the remediation.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check kernel version: uname -r (look for versions 6.7 through 6.7.3; 6.7.4+ are patched)
  2. Verify reiserfs is in use: mount | grep reiserfs (if output is empty, reiserfs is not mounted)
  3. Check for filesystem errors: dmesg | grep -i 'reiserfs\|corruption\|fatal' (look for recent filesystem corruption warnings)
  4. Confirm patch applied: grep -i 'avoid touching renamed directory' /boot/config-$(uname -r) or compare kernel version against 6.7.4 release notes

FAQ

What is CVE-2023-52591?

CVE-2023-52591 is a critical kernel vulnerability in reiserfs that allows filesystem corruption when directories are renamed without proper VFS locking, potentially leading to data loss or privilege escalation.

Is CVE-2023-52591 being actively exploited?

No, this vulnerability is not currently listed on the CISA Known Exploited Vulnerabilities catalog and no public exploits are available, though the high CVSS score (7.8) warrants prompt patching.

What versions of Kernel are affected by CVE-2023-52591?

Linux kernel versions 6.7 through 6.7.3 are vulnerable. Systems running kernel 6.7.4 or later are protected.

How do I check if my server is vulnerable to CVE-2023-52591?

Run uname -r to check your kernel version; if it shows 6.7.0 through 6.7.3 and you have reiserfs filesystems (verify with mount | grep reiserfs), your system is vulnerable.

Does Defensia detect CVE-2023-52591?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2023-52591 will appear in your dashboard with remediation steps.

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References

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