CVE-2021-47520: can: pch_can: pch_can_rx_normal: fix use after free
Vulnerability summary
CVE-2021-47520 is a high (CVSS 8.8) Use After Free vulnerability in linux. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 27.3% of scored vulnerabilities.
Not severe (CVSS 8.8, adjacent network); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 12 · Related 12Timeline
- 24-05-2024PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: can: pch_can: pch_can_rx_normal: fix use after free After calling netif_receive_skb(skb), dereferencing skb is unsafe. Especially, the can_frame cf which aliases skb memory is dereferenced just after the call netif_receive_skb(skb). Reordering the lines solves the issue.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HDiffers
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HDiffers
EPSS trend
Probability
0.34%
Chance of exploitation in the next 30 days
Percentile
27%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.34% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: adjacent network, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu88 products
- linuxAll versions (No fix recorded) | < 4.15.0-169.177 | < 5.4.0-100.113
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 4.15.0-1121.129 | < 5.4.0-1066.69
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ b21d18b51b31a24d17f883b678432fbdee3d5675, < bafe343a885c70dddf358379cf0b2a1c07355d8d | ≥ b21d18b51b31a24d17f883b678432fbdee3d5675, < 3a3c46e2eff0577454860a203be1a8295f4acb76 | ≥ b21d18b51b31a24d17f883b678432fbdee3d5675, < affbad02bf80380a7403885b9fe4a1587d1bb4f3 | ≥ b21d18b51b31a24d17f883b678432fbdee3d5675, < 3e193ef4e0a3f5bf92ede83ef214cb09d01b00aa | ≥ b21d18b51b31a24d17f883b678432fbdee3d5675, < abb4eff3dcd2e583060082a18a8dbf31f02689d4 | ≥ b21d18b51b31a24d17f883b678432fbdee3d5675, < 703dde112021c93d6e89443c070e7dbd4dea612e | ≥ b21d18b51b31a24d17f883b678432fbdee3d5675, < 6c73fc931658d8cbc8a1714b326cb31eb71d16a7 | ≥ b21d18b51b31a24d17f883b678432fbdee3d5675, < 94cddf1e9227a171b27292509d59691819c458db | 2.6.37
- linux_kernel≥ 2.6.37, < 4.4.295 | ≥ 4.5, < 4.9.293 | ≥ 4.10, < 4.14.258 | ≥ 4.15, < 4.19.221 | ≥ 4.20, < 5.4.165 | ≥ 5.5, < 5.10.85 | ≥ 5.11, < 5.15.8
Debian1 product
- linux< 5.15.15-1
3 vendors · 91 products
