Ruby Tags Array Length Psych::Emitter heap-based overflow

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.1$0-$5k0.00

Summaryinfo

A vulnerability has been found in Ruby and classified as critical. This affects the function Psych::Emitter of the component Tags Array Length Handler. The manipulation leads to heap-based overflow. This vulnerability is listed as CVE-2016-2338. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Ruby (Programming Language Software) (the affected version unknown) and classified as critical. This issue affects the function Psych::Emitter of the component Tags Array Length Handler. The manipulation with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Impacted is confidentiality, integrity, and availability. The summary by CVE is:

An exploitable heap overflow vulnerability exists in the Psych::Emitter start_document function of Ruby. In Psych::Emitter start_document function heap buffer "head" allocation is made based on tags array length. Specially constructed object passed as element of tags array can increase this array size after mentioned allocation and cause heap overflow.

The weakness was presented 09/29/2022. It is possible to read the advisory at talosintelligence.com. The identification of this vulnerability is CVE-2016-2338 since 02/12/2016. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/08/2025).

The vulnerability scanner Nessus provides a plugin with the ID 261341 (Amazon Linux 2 : ruby, --advisory ALAS2-2025-2990 (ALAS-2025-2990)), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Tenable (261341). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.1

VulDB Base Score: 7.3
VulDB Temp Score: 7.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 261341
Nessus Name: Amazon Linux 2 : ruby, --advisory ALAS2-2025-2990 (ALAS-2025-2990)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

02/12/2016 🔍
09/29/2022 +2420 days 🔍
09/29/2022 +0 days 🔍
09/08/2025 +1075 days 🔍

Sourcesinfo

Advisory: DLA 2158-1
Status: Not defined

CVE: CVE-2016-2338 (🔍)
GCVE (CVE): GCVE-0-2016-2338
GCVE (VulDB): GCVE-100-209723

Entryinfo

Created: 09/29/2022 07:58
Updated: 09/08/2025 19:08
Changes: 09/29/2022 07:58 (38), 10/25/2022 08:17 (1), 09/08/2025 19:08 (16)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Interested in the pricing of exploits?

See the underground prices here!