Executive Summary
Informations | |||
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Name | CVE-2021-47546 | First vendor Publication | 2024-05-24 |
Vendor | Cve | Last vendor Modification | 2024-06-10 |
Security-Database Scoring CVSS v3
Cvss vector : CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | |||
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Overall CVSS Score | 5.5 | ||
Base Score | 5.5 | Environmental Score | 5.5 |
impact SubScore | 3.6 | Temporal Score | 5.5 |
Exploitabality Sub Score | 1.8 | ||
Attack Vector | Local | Attack Complexity | Low |
Privileges Required | Low | User Interaction | None |
Scope | Unchanged | Confidentiality Impact | None |
Integrity Impact | None | Availability Impact | High |
Calculate full CVSS 3.0 Vectors scores |
Security-Database Scoring CVSS v2
Cvss vector : | |||
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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: ipv6: fix memory leak in fib6_rule_suppress The kernel leaks memory when a `fib` rule is present in IPv6 nftables firewall rules and a suppress_prefix rule is present in the IPv6 routing rules (used by certain tools such as wg-quick). In such scenarios, every incoming packet will leak an allocation in `ip6_dst_cache` slab cache. After some hours of `bpftrace`-ing and source code reading, I tracked down the issue to ca7a03c41753 ("ipv6: do not free rt if FIB_LOOKUP_NOREF is set on suppress rule"). The problem with that change is that the generic `args->flags` always have `FIB_LOOKUP_NOREF` set[1][2] but the IPv6-specific flag `RT6_LOOKUP_F_DST_NOREF` might not be, leading to `fib6_rule_suppress` not decreasing the refcount when needed. How to reproduce: This patch exposes the protocol-specific flags to the protocol specific `suppress` function, and check the protocol-specific `flags` argument for RT6_LOOKUP_F_DST_NOREF instead of the generic FIB_LOOKUP_NOREF when decreasing the refcount, like this. [1]: https://github.com/torvalds/linux/blob/ca7a03c4175366a92cee0ccc4fec0038c3266e26/net/ipv6/fib6_rules.c#L71 [2]: https://github.com/torvalds/linux/blob/ca7a03c4175366a92cee0ccc4fec0038c3266e26/net/ipv6/fib6_rules.c#L99 |
Original Source
Url : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-47546 |
CWE : Common Weakness Enumeration
% | Id | Name |
---|---|---|
100 % | CWE-401 | Failure to Release Memory Before Removing Last Reference ('Memory Leak') |
CPE : Common Platform Enumeration
Sources (Detail)
Alert History
Date | Informations |
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2024-10-23 02:31:26 |
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2024-10-03 02:27:57 |
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2024-10-02 02:26:24 |
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2024-09-04 02:25:55 |
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2024-08-22 02:24:25 |
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2024-08-02 13:30:53 |
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2024-08-02 01:27:25 |
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2024-06-11 00:27:50 |
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2024-05-25 00:27:24 |
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2024-05-24 21:28:51 |
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