CVE-2019-13117

Description

From CVE.org

In numbers.c in libxslt 1.1.33, an xsl:number with certain format strings could lead to a uninitialized read in xsltNumberFormatInsertNumbers. This could allow an attacker to discern whether a byte on the stack contains the characters A, a, I, i, or 0, or any other character.

Statement

RH ProdSec scores this vulnerability as "Low" due to complex prerequisites for successful exploitation.

  • The attacker must be able to supply an XSLT file to a system that automatically processes it using libxslt.

  • An xsl:number element must be present with a malformed format string designed to cause an uninitialized read in xsltNumberFormatInsertNumbers.

  • While a successful exploitation will force libxslt to process memory content as if it were a format string, the attacker cannot directly control memory contents but can observe differences in output to infer values.

  • This issue affects the version of libxslt as shipped with Red Hat Gluster Storage 3, as it includes the affected code which allows uninitialized read.

  • Red Hat OpenStack Platform versions 9, 10, 13, & 14 are marked WONTFIX as they will inherit fixes from the underlying RHEL layer.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score5.35.35.3
Attack VectorNetworkNetworkNetwork
Attack ComplexityLowLowLow
Privileges RequiredNoneNoneNone
User InteractionNoneNoneNone
ScopeUnchangedUnchangedUnchanged
ConfidentialityLowLowLow
Integrity ImpactNoneNoneNone
Availability ImpactNoneNoneNone

Vector

Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Understanding the Weakness (CWE)

Confidentiality

Technical Impact: Read Memory

Format string problems allow for information disclosure which can severely simplify exploitation of the program.

Integrity,Confidentiality,Availability

Technical Impact: Modify Memory; Execute Unauthorized Code or Commands

Format string problems can result in the execution of arbitrary code, buffer overflows, denial of service, or incorrect data representation.

Frequently Asked Questions

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