CVE Watch15 de ago. de 2026

CVE-2021-4034

Red Hat Polkit Out-of-Bounds Read and Write Vulnerability

CVSS

7.8

Alta

EPSS

94.9%

p100

KEV

SIM

27 de jun. de 2022

Exploit Today

0-100

Publicado: 28 de jan. de 2022 · Última mod.: 15 de ago. de 2026 · CWE-787 · CWE-125

EPSS · 30d

94.3%EPSS · 30 dias94.9%

2026-10-082026-11-05

Ficha do catálogo KEV

Produto

Red Hat / Polkit

Vulnerabilidade

Red Hat Polkit Out-of-Bounds Read and Write Vulnerability

Adicionado ao KEV

27 de jun. de 2022

Corrigir até

18 de jul. de 2022

Uso conhecido em ransomware

Sim

Descrição resumida

The Red Hat polkit pkexec utility contains an out-of-bounds read and write vulnerability that allows for privilege escalation with administrative rights.

Ação necessária

Apply updates per vendor instructions.

Notas

https://nvd.nist.gov/vuln/detail/CVE-2021-4034

Descrição técnica

A local privilege escalation vulnerability was found on polkit's pkexec utility. The pkexec application is a setuid tool designed to allow unprivileged users to run commands as privileged users according predefined policies. The current version of pkexec doesn't handle the calling parameters count correctly and ends trying to execute environment variables as commands. An attacker can leverage this by crafting environment variables in such a way it'll induce pkexec to execute arbitrary code. When successfully executed the attack can cause a local privilege escalation given unprivileged users administrative rights on the target machine.

Referências oficiais

CVEs relacionados

CVECVSSEPSSKEVRExploitTítuloMod.

CVE-2026-76181—

—

——0LibreOffice includes a dBASE database driver, which reads dBASE tables and their .ndx index files when a folder of dBASE files is used as a data source. A heap buffer overflow existed when an index page was read. The number of entries recorded in a page was not checked against the number of entries the page could hold, which comes from a different field of the index header. A crafted index could also make a page refer back to itself, so that reading it recursed without end. In fixed versions the index header and the entry count of each page are limited to what an index page can hold, and a page that refers back to one of its parent pages is not followed.4h CVE-2026-1167859.1 CRÍ

—

——0FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. Prior to 1.11.2, ws_read_frame() decoded a WebSocket frame's 64-bit extended payload length with a 32-bit byte swap and narrowed the result into a signed length. A value whose surviving low word became negative bypassed the signed size check and was reinterpreted as an enormous unsigned count, causing client bytes to overwrite memory beyond the 64 KiB receive buffer. Any client completing a /socket WebSocket upgrade on an enabled mod_xml_rpc endpoint reached the parser before HTTP authentication; both the module and WebSocket endpoint are disabled by default. The heap overwrite can corrupt connection pointers and crash FreeSWITCH, ending every concurrent session, although remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.4h CVE-2026-1167847.5 ALT

—

——0FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. Prior to 1.11.2, process_rtcp_report() used an RTPFB NACK packet's declared RTCP header length as its feedback-entry loop bound instead of the datagram length already validated by the caller. A short packet with an oversized declaration could drive reads far beyond the fixed 16 KiB receive buffer. Any peer able to send RTCP to an active video call can reach the flaw, including calls where remote SDP enables video RTCP even though the SIP profile has no explicit RTCP interval configured. The out-of-bounds read can crash FreeSWITCH and terminate every active call, but supplies no write primitive and does not echo the read values to the sender. This issue is fixed in version 1.11.2.4h CVE-2026-1167838.2 ALT

—

——0FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. Prior to 1.11.2, udptl_rx_packet() used a peer-controlled FEC entry count directly to fill five-entry FEC arrays in a mod_spandsp T.38 session. A larger count wrote sender-controlled error-recovery data beyond those arrays and persisted the oversized count for a later reconstruction pass. Any peer able to deliver UDPTL to an established T.38 fax session can reach the parser, including deployments using fax applications or a T.38 gateway. The memory corruption can crash FreeSWITCH and end every active call, although remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.4h CVE-2026-1167827.5 ALT

—

——0FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. Prior to 1.11.2, rtmp_i_connect() passed the first RTMP connect argument to amf0_object_get() without checking whether the AMF value was an object. A string or number in place of an AMF object caused union bytes from the message to be interpreted as node pointers and dereferenced. Any client with network access to an enabled mod_rtmp listener could send the malformed connect command before login; the module is disabled in the stock build and configuration. The invalid read reliably crashes FreeSWITCH and ends every active call, while no write, memory disclosure, or code execution has been demonstrated. This issue is fixed in version 1.11.2.4h CVE-2026-1167815.3 MÉD

—

——0FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. Prior to 1.11.2, ws_read_frame() unmasked a WebSocket payload by iterating wsh->datalen, which included frame headers, while indexing from the payload pointer. A masked frame filling the 64 KiB receive buffer could therefore XOR up to 14 bytes beyond the buffer, and the exact-capacity case also wrote a terminating NUL one byte out of bounds. The flaw is reachable before authentication when mod_xml_rpc and its opt-in WebSocket endpoint are enabled, while both features are disabled in the stock configuration. The writes remain within the same connection handle's adjacent outbound buffer, so neither a process crash nor cross-session disclosure has been demonstrated. This issue is fixed in version 1.11.2.4h