PuTTY up to 0.70 on Windows Help File input validation

Summaryinfo

A vulnerability marked as critical has been reported in PuTTY up to 0.70 on Windows. Affected is an unknown function of the component Help File Handler. Performing a manipulation results in input validation. This vulnerability is reported as CVE-2019-9896. The attack requires a local approach. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in PuTTY up to 0.70 on Windows (Connectivity Software). This affects an unknown code of the component Help File Handler. 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 confidentiality, integrity, and availability. The summary by CVE is:

In PuTTY versions before 0.71 on Windows, local attackers could hijack the application by putting a malicious help file in the same directory as the executable.

The bug was discovered 03/16/2019. The weakness was disclosed 03/21/2019 (Website). It is possible to read the advisory at lists.opensuse.org. This vulnerability is uniquely identified as CVE-2019-9896 since 03/20/2019. Attacking locally is a requirement. A authentication is needed for exploitation. The technical details are unknown and an exploit is not 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†). The entries VDB-132085, VDB-132086, VDB-132088 and VDB-132089 are pretty similar. Be aware that VulDB is the high quality source for vulnerability data.

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

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

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Exploitinginfo

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Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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