Synopsis
The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.
Description
The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.
- In the Linux kernel, the following vulnerability has been resolved: padata: Fix refcnt handling in padata_free_shell() In a high-load arm64 environment, the pcrypt_aead01 test in LTP can lead to system UAF (Use-After-Free) issues. Due to the lengthy analysis of the pcrypt_aead01 function call, I'll describe the problem scenario using a simplified model: Suppose there's a user of padata named `user_function` that adheres to the padata requirement of calling `padata_free_shell` after `serial()` has been invoked, as demonstrated in the following code: ```c struct request { struct padata_priv padata; struct completion
*done; }; void parallel(struct padata_priv *padata) { do_something(); } void serial(struct padata_priv
*padata) { struct request *request = container_of(padata, struct request, padata);
complete(request->done); } void user_function() { DECLARE_COMPLETION(done) padata->parallel = parallel;
padata->serial = serial; padata_do_parallel(); wait_for_completion(&done); padata_free_shell(); } ``` In the corresponding padata.c file, there's the following code: ```c static void padata_serial_worker(struct work_struct *serial_work) { ... cnt = 0; while (!list_empty(&local_list)) { ... padata->serial(padata);
cnt++; } local_bh_enable(); if (refcount_sub_and_test(cnt, &pd->refcnt)) padata_free_pd(pd); } ``` Because of the high system load and the accumulation of unexecuted softirq at this moment, `local_bh_enable()` in padata takes longer to execute than usual. Subsequently, when accessing `pd->refcnt`, `pd` has already been released by `padata_free_shell()`, resulting in a UAF issue with `pd->refcnt`. The fix is straightforward: add `refcount_dec_and_test` before calling `padata_free_pd` in `padata_free_shell`.
(CVE-2023-52854)
Note that Nessus relies on the presence of the package as reported by the vendor.
Solution
There is no known solution at this time.
Plugin Details
File Name: unpatched_CVE_2023_52854.nasl
Agent: unix
Supported Sensors: Nessus Agent, Nessus
Risk Information
Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched
Exploit Ease: No known exploits are available
Vulnerability Publication Date: 7/21/2021