CVE-2020-36791
What it is
In the Linux kernel, the following vulnerability has been resolved: net_sched: keep alloc_hash updated after hash allocation In commit 599be01ee567 ("net_sched: fix an OOB access in cls_tcindex") I moved cp->hash calculation before the first tcindex_alloc_perfect_hash(), but cp->alloc_hash is left untouched. This difference could lead to another out of bound access. cp->alloc_hash should always be the size allocated, we should update it after this tcindex_alloc_perfect_hash().
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-125 · Out-of-bounds read
- Record status
- Modified
Affected
- Linux Kernel < 4.4.218
- Linux Kernel < 4.9.218
- Linux Kernel < 4.14.175
- Linux Kernel < 4.19.114
- Linux Kernel < 5.4.29
- Linux Kernel < 5.5.14
- Linux Kernel 5.6
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2020-36791.md and follow it. Check whether this project is affected by CVE-2020-36791. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/0d1c3530e1bd38382edef72591b78e877e0edcd3
- https://git.kernel.org/stable/c/557d015ffb27b672e24e6ad141fd887783871dc2
- https://git.kernel.org/stable/c/9f8b6c44be178c2498a00b270872a6e30e7c8266
- https://git.kernel.org/stable/c/bd3ee8fb6371b45c71c9345cc359b94da2ddefa9
- https://git.kernel.org/stable/c/c4453d2833671e3a9f6bd52f0f581056c3736386
- https://git.kernel.org/stable/c/d23faf32e577922b6da20bf3740625c1105381bf
- https://git.kernel.org/stable/c/d6cdc5bb19b595486fb2e6661e5138d73a57f454
References
- https://blog.cdthoughts.ch/2021/03/16/syzbot-bug.html
- https://git.kernel.org/stable/c/0d1c3530e1bd38382edef72591b78e877e0edcd3
- https://git.kernel.org/stable/c/557d015ffb27b672e24e6ad141fd887783871dc2
- https://git.kernel.org/stable/c/9f8b6c44be178c2498a00b270872a6e30e7c8266
- https://git.kernel.org/stable/c/bd3ee8fb6371b45c71c9345cc359b94da2ddefa9
- https://git.kernel.org/stable/c/c4453d2833671e3a9f6bd52f0f581056c3736386
- https://git.kernel.org/stable/c/d23faf32e577922b6da20bf3740625c1105381bf
- https://git.kernel.org/stable/c/d6cdc5bb19b595486fb2e6661e5138d73a57f454
- https://syzkaller.appspot.com/bug?id=ea260693da894e7b078d18fca2c9c0a19b457534