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CVE-2023-53083

MEDIUMCVSS 5.5/10EPSS 0.19%

Last modified

CVE-2023-53083 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: nfsd: don't replace page in rq_pages if it's a continuation of last page The splice read calls nfsd_splice_actor to put the pages containing file data into the svc_rqst->rq_pages array. It's possible however to get a splice result that only has a partial page at the end, if (e.g.) the filesystem hands back a short read that doesn't cover the whole page. nfsd_splice_actor will plop the partial page into its rq_pages array and return. EPSS estimates a 0.19% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: don't replace page in rq_pages if it's a continuation of last page The splice read calls nfsd_splice_actor to put the pages containing file data into the svc_rqst->rq_pages array. It's possible however to get a splice result that only has a partial page at the end, if (e.g.) the filesystem hands back a short read that doesn't cover the whole page. nfsd_splice_actor will plop the partial page into its rq_pages array and return. Then later, when nfsd_splice_actor is called again, the remainder of the page may end up being filled out. At this point, nfsd_splice_actor will put the page into the array _again_ corrupting the reply. If this is done enough times, rq_next_page will overrun the array and corrupt the trailing fields -- the rq_respages and rq_next_page pointers themselves. If we've already added the page to the array in the last pass, don't add it to the array a second time when dealing with a splice continuation. This was originally handled properly in nfsd_splice_actor, but commit 91e23b1c3982 ("NFSD: Clean up nfsd_splice_actor()") removed the check for it.

Metrics

CVSS 3.1
5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.19%

8.7th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 5.19, < 6.1.22—
LinuxLinux Kernel>= 6.2, < 6.2.9—
LinuxLinux Kernel6.3Rc1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2023-53083?
In the Linux kernel, the following vulnerability has been resolved: nfsd: don't replace page in rq_pages if it's a continuation of last page The splice read calls nfsd_splice_actor to put the pages containing file data into the svc_rqst->rq_pages array. It's possible however to get a splice result that only has a partial page at the end, if (e.g.) the filesystem hands back a short read that doesn't cover the whole page. nfsd_splice_actor will plop the partial page into its rq_pages array and return. Then later, when nfsd_splice_actor is called again, the remainder of the page may end up being filled out. At this point, nfsd_splice_actor will put the page into the array _again_ corrupting the reply. If this is done enough times, rq_next_page will overrun the array and corrupt the trailing fields -- the rq_respages and rq_next_page pointers themselves. If we've already added the page to the array in the last pass, don't add it to the array a second time when dealing with a splice continuation. This was originally handled properly in nfsd_splice_actor, but commit 91e23b1c3982 ("NFSD: Clean up nfsd_splice_actor()") removed the check for it.
How severe is CVE-2023-53083?
CVE-2023-53083 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.
How do I fix CVE-2023-53083?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST