FreeSWITCH 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 version 1.11.1, the modverto HTTP request handler allocates a fixed 2 MiB buffer for a POST application/x-www-form-urlencoded body but accepts Content-Length up to just under 10 MiB. The body-read loop is bounded by Content-Length rather than the buffer size, producing an attacker-controlled heap overflow of up to ~8 MiB -- before the HTTP basic-auth check runs. This issue has been patched in version 1.11.1.

FreeSWITCH 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 1.11.3, sofiapresencehandlesipimessage() split the To user of an inbound SIP MESSAGE on a plus sign and treated the left side as a chat protocol selector. Selecting the api chat proto reached switchapiexecute(), allowing a peer whose MESSAGE was accepted to run FreeSWITCH API commands, including operating-system command sinks, with the daemon's privileges. Inbound chat is enabled on the stock internal and external profiles, and any authenticated profile account is sufficient; stock directory users without password material can also remove that barrier in affected configurations. The flaw permits configuration and credential disclosure, arbitrary call control, and command execution, and exploitation has been observed in the wild. This issue is fixed in version 1.11.3.

FreeSWITCH 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 1.11.3, sofiapresencehandlesipimessage() split the To user of an inbound SIP MESSAGE on a plus sign and treated the left side as a chat protocol selector. Selecting the api chat proto reached switchapiexecute(), allowing a peer whose MESSAGE was accepted to run FreeSWITCH API commands, including operating-system command sinks, with the daemon's privileges. Inbound chat is enabled on the stock internal and external profiles, and any authenticated profile account is sufficient; stock directory users without password material can also remove that barrier in affected configurations. The flaw permits configuration and credential disclosure, arbitrary call control, and command execution, and exploitation has been observed in the wild. This issue is fixed in version 1.11.3.

FreeSWITCH 1.6.10 through 1.10.1 has a default password in eventsocket.conf.xml.

FreeSWITCH 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 version 1.11.1, eslrecvevent() parses Content-Length with atol() and passes the result straight to malloc(len + 1) with no sign or magnitude check. A malicious or man-in-the-middle ESL peer can send a frame with a negative Content-Length to corrupt the heap of, or crash, any process linked against libesl, before the client has authenticated to that peer. This issue has been patched in version 1.11.1.

FreeSWITCH 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, wsreadframe() 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 modxmlrpc 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.

FreeSWITCH 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, FreeSWITCH's inbound ICE handling accepted every connectivity check without cryptographically validating its STUN MESSAGE-INTEGRITY attribute. A network peer able to reach an ICE-enabled leg's media port could forge an ICE connectivity check without SDP credentials, nominate its own address, redirect RTP and DTLS traffic, and terminate the legitimate media path. On unencrypted legs this enables eavesdropping and media injection, while all WebRTC and SIP legs that negotiate ICE are in scope. Version 1.11.2 introduces the remediation, which requires iceverifymessageintegrity=true.

FreeSWITCH 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, wsreadframe() 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 modxmlrpc 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.

FreeSWITCH 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, FreeSWITCH's inbound ICE handling accepted every connectivity check without cryptographically validating its STUN MESSAGE-INTEGRITY attribute. A network peer able to reach an ICE-enabled leg's media port could forge an ICE connectivity check without SDP credentials, nominate its own address, redirect RTP and DTLS traffic, and terminate the legitimate media path. On unencrypted legs this enables eavesdropping and media injection, while all WebRTC and SIP legs that negotiate ICE are in scope. Version 1.11.2 introduces the remediation, which requires iceverifymessageintegrity=true.

FreeSWITCH 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, sofiahandlesipirefer() placed raw Refer-To URI parameters and headers inside a sipinviteparams channel-variable block passed to switchivroriginate(). The originate parser treated a comma in the attacker-controlled value as a variable separator, allowing an authenticated caller on a bridged call to inject arbitrary variables into a newly originated leg. An injected executeonoriginate value could invoke the system dialplan application before answer and execute operating-system commands with the FreeSWITCH process privileges. SIP REFER is enabled by default, and the sender needs only a registered account and a call that takes the off-box transfer path, not administrative or Event Socket access. This issue is fixed in version 1.11.2.

FreeSWITCH 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, sofiahandlesipirefer() placed raw Refer-To URI parameters and headers inside a sipinviteparams channel-variable block passed to switchivroriginate(). The originate parser treated a comma in the attacker-controlled value as a variable separator, allowing an authenticated caller on a bridged call to inject arbitrary variables into a newly originated leg. An injected executeonoriginate value could invoke the system dialplan application before answer and execute operating-system commands with the FreeSWITCH process privileges. SIP REFER is enabled by default, and the sender needs only a registered account and a call that takes the off-box transfer path, not administrative or Event Socket access. This issue is fixed in version 1.11.2.

FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. FreeSWITCH prior to version 1.10.7 is susceptible to Denial of Service via SIP flooding. When flooding FreeSWITCH with SIP messages, it was observed that after a number of seconds the process was killed by the operating system due to memory exhaustion. By abusing this vulnerability, an attacker is able to crash any FreeSWITCH instance by flooding it with SIP messages, leading to Denial of Service. The attack does not require authentication and can be carried out over UDP, TCP or TLS. This issue was patched in version 1.10.7.

FreeSWITCH 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, udptlrxpacket() used a peer-controlled FEC entry count directly to fill five-entry FEC arrays in a modspandsp 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.

FreeSWITCH is an open-source software telecommunications platform. Before version 1.11.2, an integer underflow in  switchxmldecode()  can cause an undersized heap allocation when an XML document declares an entity with an empty replacement value. Subsequent copying overruns the allocated buffer. An unauthenticated attacker who can reach a SIP profile with presence management enabled and DTD processing permitted can trigger the vulnerability through a crafted SIP PUBLISH request. Exploitation can corrupt heap memory and terminate the FreeSWITCH process, interrupting all active calls. This vulnerability is fixed in version 1.11.2.

FreeSWITCH 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, udptlrxpacket() used a peer-controlled FEC entry count directly to fill five-entry FEC arrays in a modspandsp 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.

FreeSWITCH is an open-source software telecommunications platform. Before version 1.11.2, an integer underflow in  switchxmldecode()  can cause an undersized heap allocation when an XML document declares an entity with an empty replacement value. Subsequent copying overruns the allocated buffer. An unauthenticated attacker who can reach a SIP profile with presence management enabled and DTD processing permitted can trigger the vulnerability through a crafted SIP PUBLISH request. Exploitation can corrupt heap memory and terminate the FreeSWITCH process, interrupting all active calls. This vulnerability is fixed in version 1.11.2.

FreeSWITCH through 1.8.2, when modxmlrpc is enabled, allows remote attackers to execute arbitrary commands via the api/system or txtapi/system (or api/bgsystem or txtapi/bgsystem) query string on TCP port 8080, as demonstrated by an api/system?calc URI. This can also be exploited via CSRF. Alternatively, the default password of works for the freeswitch account can sometimes be used.

FreeSWITCH 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 version 1.11.0, a STUN packet whose declared attribute length is shorter than the structure the parser casts to causes the parser to read and write past the end of the attribute, producing an out-of-bounds memory access on the per-leg media buffer. This issue has been patched in version 1.11.0.

FreeSWITCH 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 version 1.11.0, FreeSWITCH's bundled XML parser expands nested <!ENTITY> declarations without a depth or count bound, so a small DTD can describe a body that expands exponentially ("billion laughs"). The PIDF body of a SIP PUBLISH is fed to this parser before any digest check, letting an unauthenticated network attacker force unbounded CPU and memory consumption with a single request. This issue has been patched in version 1.11.0.

FreeSWITCH 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 version 1.11.1, modverto's WebSocket frame loop intercepts a #-prefixed speed-test protocol (#SPU / #SPB / #SPE) before any authentication check. The declared payload size in #SPU was parsed with atoi() and only rejected non-positive values, so an unauthenticated peer could request up to INTMAX bytes. The server then wrote roughly size 10 bytes back during the download phase, on the order of 20 GB per request, yielding strong outbound bandwidth amplification from a short request. This issue has been patched in version 1.11.1.

FreeSWITCH 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 version 1.11.1, a single unauthenticated WebSocket frame containing a deeply nested JSON document crashes the FreeSWITCH process via stack overflow, terminating all calls and sessions on the host. The recursion drives the worker thread's stack pointer into the stack guard page, raising SIGSEGV from the kernel before any usable write primitive develops. This issue has been patched in version 1.11.1.

FreeSWITCH 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, switchcoremediaaddcrypto() passed the encoded key and salt length from an inbound SDP a=crypto attribute to switchb64decode() as the destination capacity. A zero-length key and salt made that capacity underflow, allowing the decoded attribute to overflow a fixed stack buffer with sender-chosen bytes before the call was answered. On the shipped external profile, an unauthenticated caller can reach the SDES-SRTP parser, while profiles that challenge inbound calls remain affected for senders who can authenticate; setting rtpsecuremediainbound to false removes the path, and WebRTC DTLS-SRTP legs are unaffected. The overflow corrupts memory and can crash the FreeSWITCH process, dropping every active call, although remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.

FreeSWITCH 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, rtmprtmp2rtpH264() trusted the length prefix of each inbound H.264 NAL unit without checking it against the bytes remaining in the RTMP message. An oversized declared unit underflowed the unsigned remaining-byte counter and advanced the parser beyond its receive buffer, where the next length-prefix read could crash the process. The flaw affects deployments that build and load modrtmp and accept video call sessions, commonly on TCP port 1935; placing the call requires a directory login where auth-calls is true, while no credentials are required where auth-calls is absent or false. A remote client can terminate FreeSWITCH and every active call, but the defect supplies no write primitive and memory disclosure has not been demonstrated. This issue is fixed in version 1.11.2.

FreeSWITCH 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, httpdirectoryauth() rebuilt an expected user@domain:password credential and base64-encoded it into an 80-byte buffer using an encoder without an output-length argument. A configured credential longer than 57 characters overflowed the stack before the supplied HTTP Basic password was compared. An unauthenticated client only needed to name an existing directory user on an exposed modxmlrpc HTTP listener; the module is built but not loaded by the stock configuration. The overflow can corrupt the stack and crash FreeSWITCH, ending every active call, although the overrun bytes come from the configured credential and remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.

FreeSWITCH 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, msrpparsebuffer() subtracted delimiter framing from a peer-controlled short segment whose MSRP byte range ended in without first proving the segment was long enough. The unsigned result wrapped near SIZEMAX and reached switchmsrpmsgsetpayload() as both an allocation size and memcpy length, while related pointer arithmetic could read before the receive buffer. The listener is disabled by default in msrp.conf.xml, but any deployment enabling an MSRP TCP or TLS port parses this framing before authentication. An unauthenticated network peer can corrupt memory and crash FreeSWITCH, dropping all active calls, although remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.

FreeSWITCH 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, rtmphandlecontrol() rendered an RTMP user-control message into a 200-byte stack buffer using an unbounded sprintf loop controlled by the wire message length. A body of roughly 70 bytes or more overflowed the stack before any RTMP login, because the handshake authenticates neither side. The flaw affects deployments that build and load modrtmp, which is disabled in the stock build and configuration but commonly exposes a listener on TCP port 1935 when enabled. One unauthenticated message can crash FreeSWITCH and end every active call; the constrained ASCII hex output has not yielded control-flow hijacking. This issue is fixed in version 1.11.2.

FreeSWITCH 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, modeventsocket used an unauthenticated Content-Length value directly as the allocation size for an Event Socket message body. Negative or extremely large values could overflow the terminator calculation or force an allocation failure through a helper that aborts the FreeSWITCH process. The header is parsed before the Event Socket password, so any host admitted by apply-inbound-acl can trigger termination with its first packet; the default loopback ACL limits ordinary installations to local clients. The outbound socket dialplan path is also affected when FreeSWITCH connects to a hostile application server, and process termination drops every active call until the service is restarted. This issue is fixed in version 1.11.2.

FreeSWITCH 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, processrtcpreport() 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.

FreeSWITCH 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, rtmpiconnect() passed the first RTMP connect argument to amf0objectget() 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 modrtmp 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.

FreeSWITCH 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, httpdirectoryauth() rebuilt an expected user@domain:password credential and base64-encoded it into an 80-byte buffer using an encoder without an output-length argument. A configured credential longer than 57 characters overflowed the stack before the supplied HTTP Basic password was compared. An unauthenticated client only needed to name an existing directory user on an exposed modxmlrpc HTTP listener; the module is built but not loaded by the stock configuration. The overflow can corrupt the stack and crash FreeSWITCH, ending every active call, although the overrun bytes come from the configured credential and remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.