CVE-2018-1000876

Description

From CVE.org

binutils version 2.32 and earlier contains a Integer Overflow vulnerability in objdump, bfd_get_dynamic_reloc_upper_bound,bfd_canonicalize_dynamic_reloc that can result in Integer overflow trigger heap overflow. Successful exploitation allows execution of arbitrary code.. This attack appear to be exploitable via Local. This vulnerability appears to have been fixed in after commit 3a551c7a1b80fca579461774860574eabfd7f18f.

Statement

The issue is classified as moderate severity primarily because of the unlikelihood of running a 32bit compiled objdump and/or having a compiled binary that uses 32bit compiled binutils libraries to analyze binaries from a not trusted source. Moreover, binutils does not handle privileged operations, meaning exploitation is unlikely to lead to system compromise or escalation of privileges. Additionally, the impact is localized to the application itself, without affecting the broader system or network security.

As per upstream binutils security policy this issue is not considered as a security flaw. Basically the key element of the policy that affects this is the understanding that analysis of untrusted binaries must always be done in a sandbox because the ELF format is open ended enough to make the analysis tools do anything, like including and processing arbitrary files. This eliminates the only possible vulnerability vector here, which is the possibility of a user being tricked into downloading and analyzing an untrusted ELF without sandboxing.

See the binutils security policy for more details: https://sourceware.org/cgit/binutils-gdb/tree/binutils/SECURITY.txt

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).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score47.8N/A
Attack VectorLocalLocalN/A
Attack ComplexityLowLowN/A
Privileges RequiredHighLowN/A
User InteractionRequiredNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityLowHighN/A
Integrity ImpactLowHighN/A
Availability ImpactLowHighN/A

Vector

Red Hat: CVSS:3.0/AV:L/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L

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

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Memory); DoS: Instability

This weakness can generally lead to undefined behavior and therefore crashes. When the calculated result is used for resource allocation, this weakness can cause too many (or too few) resources to be allocated, possibly enabling crashes if the product requests more resources than can be provided.

Integrity

Technical Impact: Modify Memory

If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the overflow/wraparound results in other conditions such as buffer overflows, further memory corruption may occur.

Confidentiality,Availability,Access Control

Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism

This weakness can sometimes trigger buffer overflows, which can be used to execute arbitrary code. This is usually outside the scope of the product's implicit security policy.

Availability,Other

Technical Impact: Alter Execution Logic; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)

If the overflow/wraparound occurs in a loop index variable, this could cause the loop to terminate at the wrong time - too early, too late, or not at all (i.e., infinite loops). With too many iterations, some loops could consume too many resources such as memory, file handles, etc., possibly leading to a crash or other DoS.

Access Control

Technical Impact: Bypass Protection Mechanism

If integer values are used in security-critical decisions, such as calculating quotas or allocation limits, integer overflows can be used to cause an incorrect security decision.

Frequently Asked Questions

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