Linux: Out-of-bounds Write
CVE-2023-52796 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 4f7f850611aa27aaaf1bf5687702ad2240ae442a, 4d2d30f0792b47908af64c4d02ed1ee25ff50542, 43b781e7cb5cd0b435de276111953bf2bacd1f02 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.25% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 4f7f850611aa27aaaf1bf5687702ad2240ae442a or 4d2d30f0792b47908af64c4d02ed1ee25ff50542 or 43b781e7cb5cd0b435de276111953bf2bacd1f02 or 1f64cad3ac38ac5978b53c40e6c5e6fd3477c68f, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.19.300 or 5.4.262 or 5.10.202 or 5.15.140, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 4f7f850611aa27aaaf1bf5687702ad2240ae442a; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 4d2d30f0792b47908af64c4d02ed1ee25ff50542; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 43b781e7cb5cd0b435de276111953bf2bacd1f02; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 1f64cad3ac38ac5978b53c40e6c5e6fd3477c68f; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 732a67ca436887b594ebc43bb5a04ffb0971a760; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 8872dc638c24bb774cd2224a69d72a7f661a4d56; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 03cddc4df8c6be47fd27c8f8b87e5f9a989e1458; 2ad7bf3638411cb547f2823df08166c13ab04269 up to, but not including, 18f039428c7df183b09c69ebf10ffd4e521035d2; and 1 more ranges | 4f7f850611aa27aaaf1bf5687702ad2240ae442a, 4d2d30f0792b47908af64c4d02ed1ee25ff50542, 43b781e7cb5cd0b435de276111953bf2bacd1f02, 1f64cad3ac38ac5978b53c40e6c5e6fd3477c68f, 732a67ca436887b594ebc43bb5a04ffb0971a760, 8872dc638c24bb774cd2224a69d72a7f661a4d56 |
| Linux | Linux Kernel | 3.19 up to, but not including, 4.19.300; 4.20 up to, but not including, 5.4.262; 5.5 up to, but not including, 5.10.202; 5.11 up to, but not including, 5.15.140; 5.16 up to, but not including, 6.1.64; 6.2 up to, but not including, 6.5.13; 6.6 up to, but not including, 6.6.3; 6.7 | 4.19.300, 5.4.262, 5.10.202, 5.15.140, 6.1.64, 6.5.13 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
Official description
In the Linux kernel, the following vulnerability has been resolved: ipvlan: add ipvlan_route_v6_outbound() helper Inspired by syzbot reports using a stack of multiple ipvlan devices. Reduce stack size needed in ipvlan_process_v6_outbound() by moving the flowi6 struct used for the route lookup in an non inlined helper. ipvlan_route_v6_outbound() needs 120 bytes on the stack, immediately reclaimed. Also make sure ipvlan_process_v4_outbound() is not inlined. We might also have to lower MAX_NEST_DEV, because only syzbot uses setups with more than four stacked devices. BUG: TASK stack guard page was hit at ffffc9000e803ff8 (stack is ffffc9000e804000..ffffc9000e808000) stack guard page: 0000 [#1] SMP KASAN CPU: 0 PID: 13442 Comm: syz-executor.4 Not tainted 6.1.52-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 RIP: 0010:kasan_check_range+0x4/0x2a0 mm/kasan/generic.c:188 Code: 48 01 c6 48 89 c7 e8 db 4e c1 03 31 c0 5d c3 cc 0f 0b eb 02 0f 0b b8 ea ff ff ff 5d c3 cc 00 00 cc cc 00 00 cc cc 55 48 89 e5 <41> 57 41 56 41 55 41 54 53 b0 01 48 85 f6 0f 84 a4 01 00 00 48 89 RSP: 0018:ffffc9000e804000 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817e5bf2 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff887c6568 RBP: ffffc9000e804000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92001d0080c R13: dffffc0000000000 R14: ffffffff87e6b100 R15: 0000000000000000 FS: 00007fd0c55826c0(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc9000e803ff8 CR3: 0000000170ef7000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <#DF> </#DF> <TASK> [<ffffffff81f281d1>] __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31 [<ffffffff817e5bf2>] instrument_atomic_read include/linux/instrumented.h:72 [inline] [<ffffffff817e5bf2>] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] [<ffffffff817e5bf2>] cpumask_test_cpu include/linux/cpumask.h:506 [inline] [<ffffffff817e5bf2>] cpu_online include/linux/cpumask.h:1092 [inline] [<ffffffff817e5bf2>] trace_lock_acquire include/trace/events/lock.h:24 [inline] [<ffffffff817e5bf2>] lock_acquire+0xe2/0x590 kernel/locking/lockdep.c:5632 [<ffffffff8563221e>] rcu_lock_acquire+0x2e/0x40 include/linux/rcupdate.h:306 [<ffffffff8561464d>] rcu_read_lock include/linux/rcupdate.h:747 [inline] [<ffffffff8561464d>] ip6_pol_route+0x15d/0x1440 net/ipv6/route.c:2221 [<ffffffff85618120>] ip6_pol_route_output+0x50/0x80 net/ipv6/route.c:2606 [<ffffffff856f65b5>] pol_lookup_func include/net/ip6_fib.h:584 [inline] [<ffffffff856f65b5>] fib6_rule_lookup+0x265/0x620 net/ipv6/fib6_rules.c:116 [<ffffffff85618009>] ip6_route_output_flags_noref+0x2d9/0x3a0 net/ipv6/route.c:2638 [<ffffffff8561821a>] ip6_route_output_flags+0xca/0x340 net/ipv6/route.c:2651 [<ffffffff838bd5a3>] ip6_route_output include/net/ip6_route.h:100 [inline] [<ffffffff838bd5a3>] ipvlan_process_v6_outbound drivers/net/ipvlan/ipvlan_core.c:473 [inline] [<ffffffff838bd5a3>] ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:529 [inline] [<ffffffff838bd5a3>] ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:602 [inline] [<ffffffff838bd5a3>] ipvlan_queue_xmit+0xc33/0x1be0 drivers/net/ipvlan/ipvlan_core.c:677 [<ffffffff838c2909>] ipvlan_start_xmit+0x49/0x100 drivers/net/ipvlan/ipvlan_main.c:229 [<ffffffff84d03900>] netdev_start_xmit include/linux/netdevice.h:4966 [inline] [<ffffffff84d03900>] xmit_one net/core/dev.c:3644 [inline] [<ffffffff84d03900>] dev_hard_start_xmit+0x320/0x980 net/core/dev.c:3660 [<ffffffff84d080e2>] __dev_queue_xmit+0x16b2/0x3370 net/core/dev.c:4324 [<ffffffff855ce4cd>] dev_queue_xmit include/linux/netdevice.h:3067 [inline] [<ffffffff855ce4cd>] neigh_hh_output include/net/neighbour.h:529 [inline] [<f ---truncated---
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/03cddc4df8c6be47fd27c8f8b87e5f9a989e1458
- git.kernel.org/stable/c/18f039428c7df183b09c69ebf10ffd4e521035d2
- git.kernel.org/stable/c/1f64cad3ac38ac5978b53c40e6c5e6fd3477c68f
- git.kernel.org/stable/c/43b781e7cb5cd0b435de276111953bf2bacd1f02
- git.kernel.org/stable/c/4d2d30f0792b47908af64c4d02ed1ee25ff50542
- git.kernel.org/stable/c/4f7f850611aa27aaaf1bf5687702ad2240ae442a
- git.kernel.org/stable/c/732a67ca436887b594ebc43bb5a04ffb0971a760
- git.kernel.org/stable/c/8872dc638c24bb774cd2224a69d72a7f661a4d56
Recent Out-of-bounds Write vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 8.4 High severity
- 7.8 High severity
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