Issue summary: The DTLS retransmission logic does not correctly handle a handshake message write that is suspended part-way through. The retransmitted message can be read past the message buffer and the retransmission overwrites the internal state the suspended write needs to resume correctly.

Impact summary: The retransmitted message can disclose a heap memory to the peer as plaintext handshake data or cause a crash and a Denial of Service when the read reaches an unmapped memory region.

CWE: CWE-125: Out-of-bounds Read

Description: DTLS handshake messages can be written out in multiple fragments, and a write can suspend mid-message (returning WANT_WRITE) if the underlying transport temporarily cannot accept more data. While such a write is suspended, the DTLS retransmission timer may independently fire and ask the retransmission logic to resend an earlier, already-acknowledged-as-sent message from its retransmit queue.

The retransmission logic reused the same internal buffer and position tracking as the message that was still being written, without resetting the position back to the start of the message being retransmitted. As a result the retransmission was read starting from wherever the suspended write had left off, producing a mislabelled message whose body was leftover bytes from the other, larger message still in flight - content that was never meant to be sent at that point, and which could run past the end of the allocated buffer.

Separately, even when the ret…

Issue summary: The DTLS retransmission logic does not correctly handle a handshake message write that is suspended part-way through. The retransmitted message can be read past the message buffer and the retransmission overwrites the internal state the suspended write needs to resume correctly.

Impact summary: The retransmitted message can disclose a heap memory to the peer as plaintext handshake data or cause a crash and a Denial of Service when the read reaches an unmapped memory region.

CWE: CWE-125: Out-of-bounds Read

Description: DTLS handshake messages can be written out in multiple fragments, and a write can suspend mid-message (returning WANT_WRITE) if the underlying transport temporarily cannot accept more data. While such a write is suspended, the DTLS retransmission timer may independently fire and ask the retransmission logic to resend an earlier, already-acknowledged-as-sent message from its retransmit queue.

The retransmission logic reused the same internal buffer and position tracking as the message that was still being written, without resetting the position back to the start of the message being retransmitted. As a result the retransmission was read starting from wherever the suspended write had left off, producing a mislabelled message whose body was leftover bytes from the other, larger message still in flight - content that was never meant to be sent at that point, and which could run past the end of the allocated buffer.

Separately, even when the ret…

openssl: OpenSSL: Heap buffer overflow due to signed integer overflow in Unicode output sizing openssl: OpenSSL: Denial of Service due to heap out-of-bounds read in CMS password-based decryption openssl: OpenSSL: Heap buffer over-read in ASN.1 decoding can lead to denial of service or information disclosure. openssl: PKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys openssl: CMS AuthEnvelopedData Processing May Accept Forged Messages openssl: Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler openssl: Double-free When Checking OCSP Stapled Response openssl: NULL pointer dereference in QUIC server initial packet handling openssl: NULL Dereference in Certificate Verification with OCSP Checking openssl: Possible NULL Dereference in Password-Based CMS Decryption openssl: NULL Pointer Dereference in CRMF EncryptedValue Decryption openssl: Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt() openssl: Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate openssl: FFC-DH Peer Validation Uses Attacker-Supplied q openssl: Possible Out of Bounds Read in X509_VERIFY_PARAM_set1_email() openssl: AES-OCB IV Ignored on EVP_Cipher() Path openssl: Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes openssl: Heap Use-After-Free in OpenSSL PKCS7_verify() openssl: openssl-src: OpenSSL: Memory leak leads to Denial of Service in OCSP response checking python-cryptography: python-cryptography: PKCS#7 EnvelopedData…

Affected: Ubuntu:Pro:14.04:LTS: openssl, Ubuntu:Pro:16.04:LTS: openssl, Ubuntu:Pro:16.04:LTS: edk2, Ubuntu:Pro:16.04:LTS: nodejs, Ubuntu:Pro:FIPS:16.04:LTS: openssl, Ubuntu:Pro:18.04:LTS: openssl, Ubuntu:Pro:18.04:LTS: openssl1.0, Ubuntu:Pro:18.04:LTS: edk2, Ubuntu:Pro:18.04:LTS: nodejs, Ubuntu:Pro:FIPS-updates:18.04:LTS: openssl and 18 more

DTLS Retransmits Handshake Messages From a Stale Buffer Offset