Vulnerability · Published Jun 23, 2021 · Assigned by mitre
CVE-2021-33624
Medium 4.7
In plain English
A medium-severity security flaw in the linux package (Debian). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 61% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)4.7Medium
Exploit odds (30 days)0.9%top 39.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack tooling1Public PoC
Official description
In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | linux | 5.10.46-1 | DEBIAN-CVE-2021-33624 |
| Debian:13 | linux | 5.10.46-1 | DEBIAN-CVE-2021-33624 |
| Debian:14 | linux | 5.10.46-1 | DEBIAN-CVE-2021-33624 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2021-33624 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2021-33624 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2021-33624 |
Affected products (as reported)
References
- https://www.usenix.org/conference/usenixsecurity21/presentation/kirzner
- http://www.openwall.com/lists/oss-security/2021/06/21/1
- https://github.com/torvalds/linux/commit/9183671af6dbf60a1219371d4ed73e23f43b49db
- [debian-lts-announce] 20211015 [SECURITY] [DLA 2785-1] linux-4.19 security update mailing-list
- https://github.com/benschlueter/CVE-2021-33624