GNU glibc getcwd off-by-one

CVSS Meta Temp Score
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CTI Interest Score
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8.1$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in GNU glibc. This impacts the function getcwd. This manipulation causes off-by-one. The identification of this vulnerability is CVE-2021-3999. It is possible to initiate the attack remotely. There is no exploit available. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability has been found in GNU glibc (Software Library) (affected version not known) and classified as critical. Affected by this vulnerability is the function getcwd. The manipulation with an unknown input leads to a off-by-one vulnerability. The CWE definition for the vulnerability is CWE-193. A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

A flaw was found in glibc. An off-by-one buffer overflow and underflow in getcwd() may lead to memory corruption when the size of the buffer is exactly 1. A local attacker who can control the input buffer and size passed to getcwd() in a setuid program could use this flaw to potentially execute arbitrary code and escalate their privileges on the system.

The weakness was shared 08/25/2022. It is possible to read the advisory at access.redhat.com. This vulnerability is known as CVE-2021-3999 since 11/22/2021. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 239848 (TencentOS Server 3: glibc (TSSA-2022:0203)), which helps to determine the existence of the flaw in a target environment.

Applying the patch 23e0e8f5f1fb5ed150253d986ecccdc90c2dcd5e is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at Tenable (239848). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.3
VulDB Meta Temp Score: 8.1

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

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

Exploitinginfo

Class: Off-by-one
CWE: CWE-193 / CWE-189
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 239848
Nessus Name: TencentOS Server 3: glibc (TSSA-2022:0203)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Patch: 23e0e8f5f1fb5ed150253d986ecccdc90c2dcd5e

Timelineinfo

11/22/2021 🔍
08/25/2022 +275 days 🔍
08/25/2022 +0 days 🔍
12/02/2025 +1195 days 🔍

Sourcesinfo

Vendor: gnu.org

Advisory: access.redhat.com
Status: Confirmed

CVE: CVE-2021-3999 (🔍)
GCVE (CVE): GCVE-0-2021-3999
GCVE (VulDB): GCVE-100-207139

Entryinfo

Created: 08/25/2022 09:15
Updated: 12/02/2025 22:36
Changes: 08/25/2022 09:15 (40), 09/25/2022 15:55 (11), 06/19/2025 19:41 (16), 12/02/2025 22:36 (1)
Complete: 🔍
Cache ID: 216::103

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

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