Executive Summary
| Informations | |||
|---|---|---|---|
| Name | CVE-2021-46936 | First vendor Publication | 2024-02-27 |
| Vendor | Cve | Last vendor Modification | 2024-04-10 |
Security-Database Scoring CVSS v3
| Cvss vector : CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | |||
|---|---|---|---|
| Overall CVSS Score | 7.8 | ||
| Base Score | 7.8 | Environmental Score | 7.8 |
| impact SubScore | 5.9 | Temporal Score | 7.8 |
| Exploitabality Sub Score | 1.8 | ||
| Attack Vector | Local | Attack Complexity | Low |
| Privileges Required | Low | User Interaction | None |
| Scope | Unchanged | Confidentiality Impact | High |
| Integrity Impact | High | Availability Impact | High |
| Calculate full CVSS 3.0 Vectors scores | |||
Security-Database Scoring CVSS v2
| Cvss vector : | |||
|---|---|---|---|
| Cvss Base Score | N/A | Attack Range | N/A |
| Cvss Impact Score | N/A | Attack Complexity | N/A |
| Cvss Expoit Score | N/A | Authentication | N/A |
| Calculate full CVSS 2.0 Vectors scores | |||
Detail
| In the Linux kernel, the following vulnerability has been resolved: net: fix use-after-free in tw_timer_handler A real world panic issue was found as follow in Linux 5.4. BUG: unable to handle page fault for address: ffffde49a863de28 This issue was also reported since 2017 in the thread [1], unfortunately, the issue was still can be reproduced after fixing DCCP. The ipv4_mib_exit_net is called before tcp_sk_exit_batch when a net namespace is destroyed since tcp_sk_ops is registered befrore ipv4_mib_ops, which means tcp_sk_ops is in the front of ipv4_mib_ops in the list of pernet_list. There will be a use-after-free on net->mib.net_statistics in tw_timer_handler after ipv4_mib_exit_net if there are some inflight time-wait timers. This bug is not introduced by commit f2bf415cfed7 ("mib: add net to NET_ADD_STATS_BH") since the net_statistics is a global variable instead of dynamic allocation and freeing. Actually, commit 61a7e26028b9 ("mib: put net statistics on struct net") introduces the bug since it put net statistics on struct net and free it when net namespace is destroyed. Moving init_ipv4_mibs() to the front of tcp_init() to fix this bug and replace pr_crit() with panic() since continuing is meaningless when init_ipv4_mibs() fails. [1] https://groups.google.com/g/syzkaller/c/p1tn-_Kc6l4/m/smuL_FMAAgAJ?pli=1 |
Original Source
| Url : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-46936 |
CWE : Common Weakness Enumeration
| % | Id | Name |
|---|---|---|
| 100 % | CWE-416 | Use After Free |
CPE : Common Platform Enumeration
Sources (Detail)
Alert History
| Date | Informations |
|---|---|
| 2024-04-11 00:27:51 |
|
| 2024-02-27 17:27:28 |
|
| 2024-02-27 13:27:25 |
|
