Linux Kernel up to 4.14.7 Salsa20 Encryption Algorithm crypto/salsa20_generic.c input validation

CVSS Meta Temp Score
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CTI Interest Score
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6.5$0-$5k0.00

A vulnerability was found in Linux Kernel up to 4.14.7 (Operating System). It has been classified as critical. This affects some unknown functionality of the file crypto/salsa20_generic.c of the component Salsa20 Encryption Algorithm. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on availability. The summary by CVE is:

The Salsa20 encryption algorithm in the Linux kernel before 4.14.8 does not correctly handle zero-length inputs, allowing a local attacker able to use the AF_ALG-based skcipher interface (CONFIG_CRYPTO_USER_API_SKCIPHER) to cause a denial of service (uninitialized-memory free and kernel crash) or have unspecified other impact by executing a crafted sequence of system calls that use the blkcipher_walk API. Both the generic implementation (crypto/salsa20_generic.c) and x86 implementation (arch/x86/crypto/salsa20_glue.c) of Salsa20 were vulnerable.

The bug was discovered 11/29/2017. The weakness was released 12/20/2017 as confirmed git commit (GIT Repository). It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2017-17805 since 12/20/2017. Attacking locally is a requirement. A authentication is required for exploitation. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability was handled as a non-public zero-day exploit for at least 21 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 105433 (Debian DSA-4073-1 : linux - security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 237034 (Red Hat Update for kernel-alt (RHSA-2018:2948)).

Upgrading to version 4.14.8 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be patching the affected component. A possible mitigation has been published 3 days after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (105433). Entries connected to this vulnerability are available at 109193, 110288, 110932 and 110933.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

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CVSSv3info

VulDB Meta Base Score: 6.6
VulDB Meta Temp Score: 6.5

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
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NVD Base Score: 7.8
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CVSSv2info

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VulDB Base Score: 🔍
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Exploitinginfo

Class: Input validation
CWE: CWE-20
ATT&CK: Unknown

Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

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EPSS Percentile: 🔍

Price Prediction: 🔍
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Nessus ID: 105433
Nessus Name: Debian DSA-4073-1 : linux - security update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 61643
OpenVAS Name: SuSE Update for Linux Kernel openSUSE-SU-2018:0022-1 (Linux Kernel)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
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Countermeasuresinfo

Recommended: Patch
Status: 🔍

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Upgrade: Kernel 4.14.8
Patch: git.kernel.org

Timelineinfo

11/29/2017 🔍
12/20/2017 +21 days 🔍
12/20/2017 +0 days 🔍
12/20/2017 +0 days 🔍
12/20/2017 +0 days 🔍
12/21/2017 +1 days 🔍
12/23/2017 +2 days 🔍
12/26/2017 +3 days 🔍
01/18/2023 +1849 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: RHSA-2018:2948
Researcher: syzbot.
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-17805 (🔍)
OVAL: 🔍

SecurityFocus: 102291 - Linux kernel Multiple CVE-2017-17805 Local Denial of Service Vulnerabilities

See also: 🔍

Entryinfo

Created: 12/21/2017 08:45
Updated: 01/18/2023 14:17
Changes: 12/21/2017 08:45 (84), 05/26/2020 21:03 (5), 01/27/2021 16:48 (3), 01/18/2023 14:17 (3)
Complete: 🔍

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