SARA / Free Tools / CVE / CVE-2023-5215

CVE-2023-5215 — A flaw was found in libnbd

A flaw was found in libnbd. A server can reply with a block size larger than 2^63 (the NBD spec states the size is a 64-bit unsigned value). This issue could lead to an application crash or other unintended behavior for NBD clients that doesn't treat the return value of the

CVSS
5.3 MEDIUM
EPSS
0.05% (top 85.90%)
CWE
CWE-241
Published
2023-09-28T13:55:32.462Z
Last modified
2025-11-08T08:55:24.112Z
CVSS vector
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

01What is this vulnerability?

A flaw was found in libnbd. A server can reply with a block size larger than 2^63 (the NBD spec states the size is a 64-bit unsigned value). This issue could lead to an application crash or other unintended behavior for NBD clients that doesn't treat the return value of the nbd_get_size() function correctly.

02Affected products

VendorProductVersions
Red HatRed Hat Enterprise Linux 90:1.18.1-3.el9
Red HatRed Hat Enterprise Linux 8unspecified
Red HatRed Hat Enterprise Linux 8 Advanced Virtualizationunspecified
Red HatRed Hat Enterprise Linux 8 Advanced Virtualizationunspecified

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

09References

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