PuTTY up to 0.70 Terminal input validation

Summaryinfo

A vulnerability described as problematic has been identified in PuTTY up to 0.70. Affected by this vulnerability is an unknown functionality of the component Terminal. Executing a manipulation can lead to input validation. This vulnerability appears as CVE-2019-9897. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in PuTTY up to 0.70 (Connectivity Software) and classified as problematic. This vulnerability affects an unknown code block of the component Terminal. The manipulation with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect availability. CVE summarizes:

Multiple denial-of-service attacks that can be triggered by writing to the terminal exist in PuTTY versions before 0.71.

The bug was discovered 03/16/2019. The weakness was presented 03/21/2019 (Website). The advisory is shared for download at seclists.org. This vulnerability was named CVE-2019-9897 since 03/20/2019. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 5 days. During that time the estimated underground price was around $0-$5k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 371709 (Putty Multiple Security Vulnerabilities).

Upgrading to version 0.71 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at SecurityFocus (BID 107523†). See VDB-132085, VDB-132086, VDB-132087 and VDB-132089 for similar entries. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Connectivity Software

Name

• PuTTY

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28
• 0.29
• 0.30
• 0.31
• 0.32
• 0.33
• 0.34
• 0.35
• 0.36
• 0.37
• 0.38
• 0.39
• 0.40
• 0.41
• 0.42
• 0.43
• 0.44
• 0.45
• 0.46
• 0.47
• 0.48
• 0.49
• 0.50
• 0.51
• 0.52
• 0.53
• 0.54
• 0.55
• 0.56
• 0.57
• 0.58
• 0.59
• 0.60
• 0.61
• 0.62
• 0.63
• 0.64
• 0.65
• 0.66
• 0.67
• 0.68
• 0.69
• 0.70

License

• open-source

CPE 2.3info

• 🔍
• 🔍
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CPE 2.2info

• 🔍
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Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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